there was a truck that came into our college 2 days ago that had a check engine light on, lean bank one and bank 2, and it was also skipping. It turned out that the problem was an exhaust leak on the passenger side and the driver side before the o2 sensors on each side. engines creat vaccuum on the downstroke, if you have an exaust leak then its gonna take in more air which will tell the o2 sensor to go lean, which causes skipping, so that might explain whats wrong.

 

I will check for exhaust leak when I can get this thing up in the air although I dont hear any thing that sounds much like a leak. however, at this point i will follow up on any sugestions. was your exhaust leak quite audible? was it leaking at the head to manifold or at the manifold to pipe? when tou say "skipping" do you mean a lean miss as you "tip in"to the accelerater at highway speeds? anyways, as always i appreciate the response & Ill keep you posted of any further findings.

 

its been a while since last update. temps have been up around 20-30 degrees f lately & have not had any ck engine light for a while however after experincing a miss one wet morning, miss fire #3 code popped up & rightfully so. after replacing #3 coil/boot asy. all is well. so far. time will tell if that had anything to do w/ 171/174 codes