I have a 2003 Sierra denali Quadrasteer pick up. Ran great and had bad tranny. 165k miles. Just had tranny rebuilt last week, few days passed only put about 300 miles on it. Stepped on the gas to merge on the highway and check engine
light started flashing. Pulled over it stayed flashing. Shut it down and waited like 10 minutes. Started right back up and ran and drove fine. But everytime I step on it or accelerate a little on the heavy side it will flash the check engine light. Brought it to OReilly and code scanned it. Bad o2 sensors
. Had them all replaced and still having the e sane issues. I'm completely stuck. Also had brand new MAF sensor put in.
JA: What happens when you step on the gas? Do you notice a rough idle?
Customer: Slight rough idle, everytime I get on the gas check engine will flash alot, sounds bad, not wanna accelerate well at all, and will get very bad MPG.
JA: What is the model of your '03 GM?
Customer: Sierra pick up, with Quadrasteer, and 6.0l engine with a rebuilt 4l65e transmission with less then 400 miles on it
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Replaced all o2 sensors in exhaust
, MAF sensor, checked all connections and, good fuel pressure, I have a fuel pressure gauge installed to monitor it inside my truck
JA: Anything else you think the mechanic should know?
Customer: Had the PCM/ computer in the truck flashed to all factory settings
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the GM Mechanic about your situation and then connect you two.