Hey guys,

My X-Type threw a check engine light.
It's a 2003 Automatic, 2.5l 116k miles

Scanned it got P0171 and P0172 - both banks lean.

Looking at the live data, the Short term fuel trims seem fine (near zero), however the long terms seem way high, 17-18% at idle, however when you rev it they seem to come down.

Any ideas where to look? Every lean code I've seen on the 3.0 in the S-Type is usually accompanied by the short term fuel trims being high.

Thanks in advance,

George

 

I would be checking the air filter, MAFS and check the filter box to the TB for leaks first.

 

George,

You have a classic vacuum leak. Possibly IMT o-rings, pvc hose, brake booster hose, or o-rings between upper sand lower intake manifold. What you see is normal; the short term fuel trim will approach zero as long term fuel trim increases. If you clear the codes, the fuel trims will be zeroed. Then, short term fuel trim will be high and long term trim will be low...for a while.

 

Vacuum leak like MarkC says. Go after the big 3 (IMT O-rings, brake booster hose, and PCV hose). Odds are, that is where your problem lies.

 

That's what threw me off. I DID clear the codes, and the short terms will STILL near zero, and the long terms were high... I was like HUH??

I'll take a closer look at that stuff. Are both IMT's easily accessible on the X-Type. On the S-Type you have to pull the cowl and have gumbys hands.... By the PCV hose you mean the big plastic elbow right.

Seems like the steering rack is making noise when the car is COLD too. Ugh I think it may be time to get another winter beater.

Take care,

George

 

The IMT's are visible from the passenger side held in by 2 bolts each. Very easy to replace O rings, just remove bolts and wiring harness, the top valve will come all the way out and you can remove old O ring and install new one from the inside of valve. The lower valve will only come out far enough to get to the O ring, just cut the old ring off, then slip the new one over the ears of the valve housing one ear at a time. Then bolt everything back in place hook up the wiring harness and job is done, about 15 minute job.

 

Mine was the crankcase breather hose. I pulled the decorative cover off and the hose was toast. The new one from the dealer is about 18 US and reinforced very well, much better than the original hose. It was an easy fix.

 

Please post your findings.

 

Did we find a cause?

 

I ordered IMT O Rings and a crankcase breather hose. This isn't my daily driver and I really don't have time to mess with cars during the week. I should have the parts today or tomorrow, and I'll swap them out this weekend if I have time and let you guys know how it goes from there.

Take care,

George