alec_b Posted June 1, 2011 Report Share Posted June 1, 2011 SES light popped up while I was sitting in traffic yesterday, it was a very humid day ambient temp were around 86*. Stayed on for a couple hours but was gone by the evening. I pulled the code this morning at work, P0172 System too rich Bank 1. Quick search of identifix seemed to point towards a failing MAF, but the first tip was to check the MAF screen for debris, which I did and it was clean. I didn't take the time to check trims with the scanner, but it never ran any different and the light like I said went off on it's own. I did check the FPR and it's not leaking. So MAF is one idea, I'm thinking maybe a lazy O2 might do it, sending false rich readings to the PCM. Anything else to check? Quote Link to comment Share on other sites More sharing options...
BXX Posted June 1, 2011 Report Share Posted June 1, 2011 When was the last time you changed your air filter?? Quote Link to comment Share on other sites More sharing options...
alec_b Posted June 1, 2011 Author Report Share Posted June 1, 2011 It's a cone filter that was on the car when I got it, it's clean and not over oiled that I can see. I did blow it off with air just in case. Quote Link to comment Share on other sites More sharing options...
BXX Posted June 1, 2011 Report Share Posted June 1, 2011 Get a scan tool on there, and see what the trims are. Seeming it has a cone filter on there, remove and clean the MAF. Cone filters = dirty and oily MAFs. Even the slightest bit of oil that you cant see will mess with the readings. I always cleaned my MAF every oil change for that reason with my cone filter. Cause if I didnt, around the 5000mile mark, my fuel trims would start heading rich... Ditch the oil style cone filter, and grab a AEM Dryflow unit. Quote Link to comment Share on other sites More sharing options...
alec_b Posted June 1, 2011 Author Report Share Posted June 1, 2011 AEM dryflow, check. I never really liked the oiled units anyways, I get SO many issues at work because of dirty MAF's. I have the day off tomorrow, I'll stop up and throw the scanner on it and see what my trims are. I seem to remember though, last time I had the scanner on it for my cam sensor code that the LTFT's were somewhere around 7%, even though the STFT's hovered right around +/- 2%. Quote Link to comment Share on other sites More sharing options...
BXX Posted June 1, 2011 Report Share Posted June 1, 2011 IIRC its not until 15% minimum that it will set the code, and I think it has to sit at 15% or more for a fail amount of time. Quote Link to comment Share on other sites More sharing options...
alec_b Posted June 1, 2011 Author Report Share Posted June 1, 2011 15% sounds about right, I can't IMAGINE that it's be running that rich for that long and not start missing, or smelling terrible or blowing black smoke. I'm glad it went away though. Quote Link to comment Share on other sites More sharing options...
BXX Posted June 1, 2011 Report Share Posted June 1, 2011 Around 20-25% is where you will generally notice something is way fuxored:lol: However, its prolly a MAF issue, so it prolly wasnt really running rich, it was just going off of what the MAF was reporting to the PCM. Quote Link to comment Share on other sites More sharing options...
alec_b Posted June 1, 2011 Author Report Share Posted June 1, 2011 That's what I was thinking. I'll pull the MAF again and clean it after I check the trims and reset the ECM, and see where my trims land after that. Quote Link to comment Share on other sites More sharing options...
alec_b Posted June 1, 2011 Author Report Share Posted June 1, 2011 Got some numbers: Idle- STFT hovered between +3 and -3 LTFT was sitting right at -7 MAF was at 3.79 g/s 2111 hz at idle 2500 RPM - STFT -3 to -7 LTFT -4 steady MAF 11.25 g/s 3315 hz Anything look off? Quote Link to comment Share on other sites More sharing options...
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