SES light same code again.

[03stx]

I have gotten this code (p0171) a few times now and cannot diagnose the problem. A few months ago I reoiled my filter and used too much oil and the codes (p0171 & p0174) came on, so I cleaned the MAF and that was it. Then the code came back on like a month later, so I cleaned the MAF and it seemed to work again. well about 150 miles ago the light came back on, so i cleaned the MAF and it stayed off for about 150 miles then just came back on. This time it was only p0171. I dunno what the problem is. I checked over the entire engine bay and no vacuum leaks were found. The truck runs perfect other than a slightly low idle of about 550-600 rpms. occasionaly it idles slightly rough but nothing bad. I have cleaned the IAC and the throttle body. Any suggestions? Could it be a dirty EGR? how do I clean that?

[WA 2 FST]

This is a LTFT (long-term fuel trim) lean code. I haven't seen this be from a MAF problem (unless there was a vac leak b/w the MAF sensor and the throttle body). I have seen this code thrown due to a vac leak (I'm sure you've checked all the various hoses, but I'd check them again) or O2 problems.

[03stx]

I have been told to check the hose that connects to the lower back of the intake.

[WA 2 FST]

I would check that hose and _any_ hose that connects to the intake. If a hose is disconnected or old and has worn so that air can pass through it, then it will cause a lean condition.

[99WhiteBeast]

I have been told to check the hose that connects to the lower back of the intake.

Good luck that thing is a PITA to get to. Find someone with small hands and long arms