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Nas Escobar

P1405 Code

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Nas Escobar

So a couple weeks ago, the engine in my 94 Cutlass has had a notable but small shake at idle, as if it wanted to turn off. It disappeared as I would accelerate. I checked the spark plugs and cables, and all seemed good, so my next step was to check the vacuum lines. I noticed the brake booster vacuum hose felt frail and would make a whistle every time I pressed the brakes. I naturally looked for a hose to replace the old one, and in between that was when the shake got worse. The last time I drove the car, the SES light turned on and triggered P1405 - EGR 3. That same day, I swapped the hose but it was after the fact that it turned on the SES light.

 

So now I'm at a loss. I thought it had to do with that vacuum line but turns out while that fixed the whistle when I pressed the brakes, I'm still having a shake on the engine, as if it were a misfire. The weird part is that it stumbles when I floor it until 2500 rpm, then the engine revs easier but still feels a bit restricted.

 

So I'm at a loss here since searching brings up nothing except for things for Ford, which interesting enough P1405 is a common issue on Ford EGR's and it usually ends up being a "DPFE SENSOR", but nothing comes up for that code for a GM car. So with that said, where should I look, or should I replace the EGR?

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rich_e777

The EGR valve is cleanable for 1994. I`ve taken mine apart several times to get any build up out. There is one triangle shaped gasket in the middle of the thing that I haven't been able to find. But Permex has some nice high temp copper based sealant that has worked good to supplement that particular seal. And all the pistons are the same and there is really no way to install anything wrong other than that middle gasket. I used a wire brush. To get up into the solenoid chambers after the pistons are removed I used a barrel cleaning brush from my gun cleaning kit. I don't think build up could get up there but better safe than sorry.

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RobertISaar

sounds like your EGR 3 solenoid could be stuck fully or partially open. pull the whole pack and you'll probably see the largest of the 3 orifices doesn't have the valve all the way down.

 

fairly common, but i find EGR 1 to be the most problematic on average.

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Nas Escobar

I'll pull the EGR when I get home.

 

Can I spray brake cleaner in there or do I need to brush it off?

 

Before I get a new EGR, Id look into cleaning all the passages, in the intake. I bet its clogged with carbon.

 

This would require me to remove the plenum, wouldn't it?

 

Sent from my HTC Sensation using Tapatalk

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1990lumi

if you have the same egr as i do on my 90 lumina then you just have to take off two bolts and spray down the inside of the egr with i used carb and choke cleaner and a toothbrush to scrub it and sprayed it down again very well a few times let it try cleaned off old gasket and just reinstalled it

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Nas Escobar

So I took it off, and this is what I saw. The valves fell out when I pulled up the top of the EGR connector.

 

DSC_0236.jpg

 

I sprayed it all down and brushed it a bit. I might do it again tomorrow, but no effect when I put it in tonight.

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rich_e777

Check each piston and see if the seat freely moves about, its suppose to, also check this area for damage. If its as clean as you can get it and you don't have any leaks then I`d grab another EGR from a JY. I`ve never heard of one going bad in my years here. Since its just a solenoid err solenoid cluster there must be a way to test it but I don't know how.

 

The whole damn system is stupid to me, using exhaust gases to lower combustion temperature to lower emissions. I`ve been wanting to delete mine for years.

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Nas Escobar

Update!

 

Ive cleaned the EGR, nothing, replaced the EGR and it stopped losing power but still shook and sometimes felt anemic... so I replaced the "I dont trust it" reman MAF and it helped considerably with the powerloss BUT I still trigger P1405. The service manual has a way to test the EGR for connection issues, but idk how to do em on Tunerpro. Other than cleaning the EGR tube, which I assume is the tube that runs from the EGR to the exhaust pipe, what else can I do? I reallg dont wanna mess with that tube since its hard to reach...

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RobertISaar

there are a few ways you could test it, depending on the equipment available. the ADX i uploaded for the 94-95 LQ1 application does have mode 4 commands in it for testing the EGR solenoids. i believe the engine needs to be running for them to be actuated, so that will have to happen, then mode 4 commands should be able to be sent.

 

otherwise, you could manually apply +12V and ground to the correct pins to get them to cycle. can do that engine off and probably hear the difference between a stuck and moving solenoid, but engine running would be best to assure that EGR gasses are actually getting into the intake.

 

 

 

the weak feeling you're getting from the engine is likely to be the PCM pulling timing that would otherwise not cause knock with functional EGR. if it still happens under the coolant temp where EGR is disabled, then that is telltale that something else is likely causing it.

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Nas Escobar
there are a few ways you could test it, depending on the equipment available. the ADX i uploaded for the 94-95 LQ1 application does have mode 4 commands in it for testing the EGR solenoids. i believe the engine needs to be running for them to be actuated, so that will have to happen, then mode 4 commands should be able to be sent.

 

I'll need a walk through on that, I can't manipulate TP5 for the life of me... nor this tablet I bought for tunerpro for that matter.

 

the weak feeling you're getting from the engine is likely to be the PCM pulling timing that would otherwise not cause knock with functional EGR. if it still happens under the coolant temp where EGR is disabled, then that is telltale that something else is likely causing it.

 

The interesting thing is that it feels weak only between 1500-2700 rpm and only if the engine drops to 750rpm. It starts around 1000rpm usually and drops once I use it. The code is concurrent with the anemic feeling, if I drive it hard the engine feels strong and no codes are set, P1405 disappears.

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RobertISaar

enough throttle will disable EGR, so that makes sense. the test only runs during coastdown but the PCM can still attempt to use the solenoids when appropriate until they fail/pass enough tests.

 

inside of tunerpro.... assuming you have some kind of basic communication with correct ADX going already, all you need to do is make sure the "Data acquisition send command" menu option is selected(right-click in the command buttons area to select what sections are visible, the last one is the one you want).

 

now you should have a selection box and a send button. you should be able to send any command i setup while the engine is running and have the PCM act upon it. keep in mind sending new commands will cause the last command sent to now be ignored(so idle speed->1600 and then turning on EGR solenoid 2 would cause the normal idle speed to be commanded again along with EGR2 turning on).

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Nas Escobar

I see... so that is what causes the code to be inconstant...

 

In this case, would EGR delete cause it to run better?

 

I can do that much, since I can get codes and stuff, but the commands I just find confusing... I'll try to play around with it tomorrow once I have time.

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Go4DaMo

My moms 92 LHO is currently sputtering bad & driving at half power. When you floor it, it's as if you're pulling a boat. Occasionally stalls, too. This happens cold or hot.

Any idea what is causing this? Really need to get it solved ASAP, as it's her only vehicle.

Was thinking coil pack or injectors...my mechanic's diagnostic test came back inconclusive on those.

Also, coil pack was missing 1 bolt which allowed some flex when pulling plugs off it to try to pinpoint misfire...replaced that bolt, but being like that for possibly a lengthy time could have caused damage to the ignition module behind it, right?

And if this should be a separate thread, my apologies.

I screenshot 3 parts of this thread in case signs point to MAF or EGR and I need to take that route.

Thanks.

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rich_e777
enough throttle will disable EGR, so that makes sense. the test only runs during coastdown but the PCM can still attempt to use the solenoids when appropriate until they fail/pass enough tests.

 

inside of tunerpro.... assuming you have some kind of basic communication with correct ADX going already, all you need to do is make sure the "Data acquisition send command" menu option is selected(right-click in the command buttons area to select what sections are visible, the last one is the one you want).

 

now you should have a selection box and a send button. you should be able to send any command i setup while the engine is running and have the PCM act upon it. keep in mind sending new commands will cause the last command sent to now be ignored(so idle speed->1600 and then turning on EGR solenoid 2 would cause the normal idle speed to be commanded again along with EGR2 turning on).

 

Took me a few minutes before I realized I was running an older version of TPRT:lol: Updated now though.

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rich_e777
My moms 92 LHO is currently sputtering bad & driving at half power. When you floor it, it's as if you're pulling a boat. Occasionally stalls, too. This happens cold or hot.

Any idea what is causing this? Really need to get it solved ASAP, as it's her only vehicle.

Was thinking coil pack or injectors...my mechanic's diagnostic test came back inconclusive on those.

Also, coil pack was missing 1 bolt which allowed some flex when pulling plugs off it to try to pinpoint misfire...replaced that bolt, but being like that for possibly a lengthy time could have caused damage to the ignition module behind it, right?

And if this should be a separate thread, my apologies.

I screenshot 3 parts of this thread in case signs point to MAF or EGR and I need to take that route.

Thanks.

 

I have no qualms about derailing a thread but your own might be better. It might need a new set of wires and just looking at the connection wont confirm could or bad which is probably what your mechanic did. You can test the resistance on them with a multimeter, same with the coil packs. I don't know the spec numbers for the LHO components but for my 7mm wires IIRC its 15 Ohms and for the coil packs it is about 12.5Ohms. How do the spark plugs look? Fluids ok? Fuel filter been changed? Test fuel pressure.

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RobertISaar
I see... so that is what causes the code to be inconstant...

 

In this case, would EGR delete cause it to run better?

 

I can do that much, since I can get codes and stuff, but the commands I just find confusing... I'll try to play around with it tomorrow once I have time.

 

a proper EGR delete(meaning, letting the PCM know not to even attempt to operate the EGR solenoids or add EGR-specific spark advance or remove EGR-specific fuel), if that is the problem that would solve it.

 

two screenshots could probably explain most of what is necessary if you're already as far as being able to consistently connect and read data. at the moment, that's too much time, after i'm done working for the day i might be able to pull it off.

 

My moms 92 LHO is currently sputtering bad & driving at half power. When you floor it, it's as if you're pulling a boat. Occasionally stalls, too. This happens cold or hot.

Any idea what is causing this? Really need to get it solved ASAP, as it's her only vehicle.

Was thinking coil pack or injectors...my mechanic's diagnostic test came back inconclusive on those.

Also, coil pack was missing 1 bolt which allowed some flex when pulling plugs off it to try to pinpoint misfire...replaced that bolt, but being like that for possibly a lengthy time could have caused damage to the ignition module behind it, right?

And if this should be a separate thread, my apologies.

I screenshot 3 parts of this thread in case signs point to MAF or EGR and I need to take that route.

Thanks.

 

hard to tell Sam, depends on how the mechanic tested everything. a 92 3.1 won't have a MAF, so that isn't it. crap power at all times would lead me to believe ignition problem or exhaust restriction, but fuel problems aren't unheard of either, LH0 injectors love to internally short.

 

Took me a few minutes before I realized I was running an older version of TPRT:lol: Updated now though.

 

V4 and V5 have a very different feel and very different for datalogging in general.

 

I have no qualms about derailing a thread but your own might be better. It might need a new set of wires and just looking at the connection wont confirm could or bad which is probably what your mechanic did. You can test the resistance on them with a multimeter, same with the coil packs. I don't know the spec numbers for the LHO components but for my 7mm wires IIRC its 15 Ohms and for the coil packs it is about 12.5Ohms. How do the spark plugs look? Fluids ok? Fuel filter been changed? Test fuel pressure.

 

15KOhms for factory style plug wires seems believable. coil pack secondaries(the terminals the plug wires slip onto) at 12.5Kohms is also believable. i would grab better data at the moment, but time is really short in the mornings.

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Go4DaMo

Thank you both for the help! I'm at a loss for the problem with your 3.1, but I'm anxious to see what fixes it!

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Nas Escobar
a proper EGR delete(meaning, letting the PCM know not to even attempt to operate the EGR solenoids or add EGR-specific spark advance or remove EGR-specific fuel), if that is the problem that would solve it.

 

two screenshots could probably explain most of what is necessary if you're already as far as being able to consistently connect and read data. at the moment, that's too much time, after i'm done working for the day i might be able to pull it off.

 

Well, I did run tests with my tablet, I did manage to understand what you were talking about. I forced EGR3 on, and the engine felt as if it was choking for air. I turned it off, there was no issues at all. I forced EGR1 on and the car stumbled down in RPM then shook. It was gone once I turned it off.

 

I guess at this point, I'm at a loss. If I turn off all EGR valves, the problem is gone, and even though it still feels lacking a bit of power in the same powerband (1500-2600), it doesn't feel forced. I also notice if I make the idle at 600, the car smells like sulfur. It has a distinct almost rotten egg like smell. It had me thinking it was the catalytic converter for a bit. If I idle it at 1400, the engine is as smooth as it could be, although it does feel a little bit lacking but not as much. No smells, no shake, nothing. The shake is persistant at stock idle (about 750/800 RPM).

 

So where should I look next? Should I just clean that EGR tube? It has a new EGR valve.

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RobertISaar

you mention 1 and 3, did you try 2 as well? the code is for 3, but you never know.

 

smelling sulfur would indicate the cat is getting too hot..... that shouldn't happen at idle unless you have some serious fuel trimming going on, but that should resolve itself pretty quickly.

 

http://imgur.com/eh8ySS8,jQwK8W7,paaW2GY

 

anyways, now that you have solenoid control, that should be able to be stepped through.

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Nas Escobar

I have the manual. Thanks for the pic though. Idk how to do "misc. test" on the Tunerpro there. Didn't see that on the commands.

 

I did try EGR2, and it felt just like EGR3. It's only one that makes it shake as if it's gonna die (but never does).

 

As far as the whole sulfur thing, should I suspect a bad cat or no? I've suspected the cat since the issue started, because it started off as a pronounced shake that would go away while driving.

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RobertISaar

2 and especially 3 should make the engine run horribly, if not die immediately upon activation. 1 tends to make the engine lopey.

 

do you happen to have a backpressure guage or at least a vacuum guage? those would help rule out/confirm a restricted exhaust due to the cat. could also unplug and remove the O2 sensor from the pipe to see if that improves anything. if the cat were plugging, i would expect to see more and more power lost with increasing throttle angle.

 

you have any saved datalogs lying around?

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Nas Escobar

My hard drive took another dump and I returned the tablet since it was too small. :( Sadly, I have to get some sort of laptop or w.e. to get another datalog.

 

But no,I don't have a back pressure gauge.

 

Define horribly though. I just get a loss of power, no rough idle, no lope, nothing.

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Hairdo12
My moms 92 LHO is currently sputtering bad & driving at half power. When you floor it, it's as if you're pulling a boat. Occasionally stalls, too. This happens cold or hot.

Any idea what is causing this? Really need to get it solved ASAP, as it's her only vehicle.

Was thinking coil pack or injectors...my mechanic's diagnostic test came back inconclusive on those.

Also, coil pack was missing 1 bolt which allowed some flex when pulling plugs off it to try to pinpoint misfire...replaced that bolt, but being like that for possibly a lengthy time could have caused damage to the ignition module behind it, right?

And if this should be a separate thread, my apologies.

I screenshot 3 parts of this thread in case signs point to MAF or EGR and I need to take that route.

Thanks.

 

I wonder who the asswipe was would forget a coil pack bolt.... Or rather got lazy BC the ac line was in the way. :lol: What did they replace anyways? He'll I'll just txt ya.

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