The Plight of the lean codes
#11
Do you have lean codes for both banks or just one bank? An exhaust leak on one bank, will not effect the fuel trims on the other bank. So if both banks are lean, then you either have exhaust leaks on both sides, or you have a global issue (effects both banks, i.e. MAF sensor, intake leak, low fuel pressure, etc...).
Both banks are lean. Based on the images I posted - do my fuel trims look abnormal ?
I like your comments. It at least centers me. It doesn’t seem plausible that I have leaks on both sides (unless it’s exhaust manifold ?)
#12
When I bumped into the lean code issue, while it was only one bank, i went ahead and checked exhaust manifold bolts on both side and they were both on the loose side - so don't necessarily dismiss them. I doubt it's your issue but it worth a check. Also, I didn't see where you posted the actual lean codes, are they pre or post cat?
#14
#15
Exhaust leaks will certainly cause a lean code. Its called an Oxygen Sensor because it detects Oxygen. Exhaust goes through the manifold in "pulses", which is why exhaust leaks make a "puff puff" sound. When its not expelling exhaust, its drawing outside air in. This air drawn in, contains 21% Oxygen and the sensor doesn't know there is a leak, it just assumes its from the engine and tells the ECU that the fuel mixture is too lean.
Thread
Thread Starter
Forum
Replies
Last Post