I know this question has been thrown around the forums, but I wanted to bring it up and ask a little more. I am getting the PO171 - too lean message on my 2006 i5 H3 with 80K miles. I recently noticed that intermittently, the RPM's are low and its acting like it wants to die when rolling to a stop. Also have notices a black carbon buildup around the exhaust tip. I have the plastic K&N system installed with oiled filter. It was pre-oiled and I have not had to clean it yet, but I am about to.

Yesterday I was looking at the filter and noticed a heavy buildup of oil residue on the distrubutor cap and also around the rubber coupler of the intake, where it leads in to the engine. Any thoughts?

 

How many miles on the filter without cleaning it?

H3s do not have a distributor, and therefore, no distributor cap.

You probably are overdue for an air filter cleaning (very important when using K&Ns) and also need to clean the MAF and Throttle Body. Your P0171 has nothing to do with false stalling, but your TB and MAF do.

A really nasty dirty air filter can throw a P0171, more likely a leak downstream from the MAF.

 

About 5-8k on the filter without cleaning.

I broke everything down since posting and have cleaned the filter. The intake was loose, so I definately had a leak.

Can you give me some tips on how to clean the throttle body and MAF. What solutions to use. Maybe some help identifying the throttle body.

It is my best understanding that the blackness on the exhaust tip can be due to the computer not getting the correct air/fuel mixture due to the PO171 and I am assuming a dirty MAF?

Thanks!

 

I found this regarding cleaning.

H3 Throttle body and MAF sensor cleaning

 

Every fuel injected GM vehicle made puts black on the exhaust tip, they all run rich. 5-8K on the filter is not that bad unless you live in the dusty southwest.

"Search" is a wonderful thing.

There are tons of threads on how to clean a H3 MAF and TB. You do not even need to remove the TB to do it, but you will have a better result when you do.

BTW, the OP in your link thread had what I would call a pretty clean TB before he even started. When they get to the point of interfering with proper idle and performance they will be black all around the TB idle plate and bypass.

 

The TB was pretty dirty on the back side. I was wondering about that dude's picture. If he considered that dirty, then mine was really dirty! I live in Rck Springs, WY. We have dunes about 30mins away, so it's a dusty/sandy place to live. Thanks for your help.

 

Cool............ so does your Sandman handle play in with the dunes?




We got dunes in MI as well.

 

You got it! I don't have any Hummer videos, but check this out!

 

Necro bumping my old thread as the P0171 is back. I have cleaned the MAF, throttle body, K&N as I normally would, clear the codes and after about a days worth of driving it re-appears. Note I also recently changed out the 02 sensor (upper/passenger side), with a new Bosch.

I've done this several times now and it keeps reappearing. I think I maybe have an air leak in the K&N as there is an oily buildup, which I suspect is residue from the K&N. It happens where the gasket for the intake and the throttle body mate. Can I replace plstic K&N intake tube, or how about this... is there a non-oiled K&N filter/intake system that I can replace the K&N with that is better?

 

Most oil residue problems with K&N's are from over-oiling. I've run K&N's on every motorcycle and ATV I've owned in the last 40+ years (including 6 years professionally racing M/C in the SoCal deserts), as well as every 4wd street legal vehicle, and have never once had an issue with oil fouling the MAF or showing up anywhere else in the intake. I've also never had so much as a spec of dirt, dust, or sand show up in the intake. BUT, it is a fine line with K&N's between too much oil and not enough; many people have a hard time finding that line, with most erring on the side of over-oiling.