gmrulz4u Posted May 20, 2004 Report Share Posted May 20, 2004 I've owned my Cutlass for over 4 years now and today was the first time that I finally got a OBD Trouble Code. I was just driving to drop my girlfriend off at work in the morning and noticed the SERVICE ENGINE LIGHT. I have an AutoMeter Air/Fuel gauge installed and noticed right away that it was stuck in the "RICH" and wasn't moving. So I checked the code and it indeed was code 45, "Oxygen Sensor indicating a Rich exhaust". I drove to my sisters work to borrow a paper clip from her to check the code. The light stayed on the entire time it took me to get there...about 15 minutes. But since I shut the car off at her work, the light hasn't come on since!? I got a new O2 Sensor about a year and a half ago. I've pretty much known that my O2 Sensor has been indicating richness for quite a while because when I used to always hook a scanner up while driving, I would see the ECM lower the injector pulse because it was being told that it was running too rich. I've checked my fuel pressure and it's fine. I checked the FP regulator and it's fine. There's no injector leaks. And I have pretty good gas mileage. So, I'm guessing that I'm really NOT running rich and that the O2 Sensor is indeed "dead". But I thought I'd ask you guys what you think? I'll probably just replace the sensor and see what happens but I hate replacing GOOD parts... I've been watching my A/F Gauge closely lately. What I notice a lot is this: I will come to a complete STOP, and the O2 will stick RICH for about 6 or 7 seconds and NOT move at all...then it will slowly start to go the other way(LEAN) and eventually go fast again... So it's almost like for some reason when I am idling, my O2 doesn't respond right away?? The ONLY other thing I'm thinking it might be is the IAC Valve. Perhaps it's not letting in enough air or something. Or the number of "Counts" that the ECM thinks it's adjusted to is incorrect? Because I always try to remember that running RICH can be one of TWO things: too much FUEL, or too little AIR. The second one is what a lot of people seem to forget... Any recommendations?? THANKS! Quote Link to comment Share on other sites More sharing options...
Canada Posted May 20, 2004 Report Share Posted May 20, 2004 You usally don't get rich conditions from to little air......it'd barely run for that to happen. Voltage increases with richness.....so you are getting a higher than normal level of voltage from the sensor. The material inside the O2 sensor is what makes the voltage (we aren't talking much here......its a range of 0-1 volt)......its not supplied from the battery. *Normally* when a sensor fails, it indicates a lean condition. I think you are in fact rich (I could very well be wrong)........do you notice any black clouds of smoke out the exhaust when you let off the throttle or shift? what color are your spark plugs? The code has NOT popped since the other day for you. So until it happens again......I wouldn't worry about it. Quote Link to comment Share on other sites More sharing options...
gmrulz4u Posted May 20, 2004 Author Report Share Posted May 20, 2004 Yeah it only happened once today...so I'll wait and see if it comes on again... GM states that the sensor can fail 3 ways...one of which is sticking RICH because silicone contaminents... For the past year I've been trying to figure out what is going on with my slightly RICH running engine...I've posted at least 10 times on various car message boards about it...I never got a Trouble Code but I kept seeing on my Scanner that the "Block Learn" figures were way too low...indicating that for some reason the ECM was taking fuel away because the O2 was indicating richness... It used to just be that when I was idling or decelerating...the O2 would stick rich for too long...but today for the first time it was stuck rich for about 15 minutes even while accelerating...it has never done that before or since...so this is the main reason that I think it's the sensor itself... If my EGR was stuck open, which apparently is another cause of the code 45, I believe I would get a "shaky" idle, but I don't get any of that...the only thing I kind of get is poor accelerating when the engine is hot(above 180 degrees)... I'm at a loss...that is why I gave up on trying to figure out what was going on for the past 2 months...but now that I got the code, it looks like I'll be diving back in to it... One question though...I have to have my emissions test next month, and was thinking, if my O2 is indicating a FALSE rich condition, wouldn't I pass really easily?? Because the ECM will limit the fuel even though it shouldn't...?? Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 20, 2004 Report Share Posted May 20, 2004 I'd get it fixed ASAP, because in some states, if you get a SES or CEL while the emissions test is in progress, you automatically fail, regardless of reason. I have a bad IAC, and I managed to make it all the way through the emissions test without it throwing a SES light, simply because my car did not idle for a sufficient length of time. If it idles for awhile, it'll be at around 800-900, and suddenly jump (audibly and visibly) to about 1100 or so, and spit a SES light with 35 code. Quote Link to comment Share on other sites More sharing options...
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