First things first, here's what I'm experiencing: My 2001 S10 4.3 ZR2 pickup appears to lose power and has troubles climbing in RPMs above about 3,000. Trucks starts and idles perfectly. It feels strong and runs hard up until about 3,000RPM at which point the power drops off and it has a slow climb to redline. This issue was magnified when I attempted to go up in elevation outside Denver. The truck began to hiccup and stutter in an attempt to climb the hills. Normal day to day driving to/from work there is no signs of issues. Only noticeable when needing higher RPMs. The only engine code I'm receiving is both bank1 & bank2 O2 sensors voltage low (or lean).
I've replaced both front O2 sensors. I've checked the fuel pressure and it was consistently 50psi+ as I drove around locally for a brief amount of time. (Perhaps I need to perform a longer test.) MAF sensor was thoroughly cleaned as well as the sensor behind it. I've got a new distributor cap & rotor as well as a new fuel filter arriving in the mail tomorrow.
Any experiences or direction you all could share would be greatly appreciated. I'd really like to save myself from throwing a bunch more money into this thing. I'd like to get it running well so I can sell it soon.
Edited by Motodrew, 12 April 2017 - 12:46 AM.