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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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1 cylinder falls on its face when car gets hot get code

Customer Question

1 cylinder falls on its face when car gets hot get code p0300 p0171 b1 cat was clogged solid changed b1 cat and sensors changed plugs did fuel injector cleaning checked intake for leaks still same problem
JA: Just to clarify, can you actually see the leak?
Customer: what leak
JA: What is the model/year of your Chevy?
Customer: 2005 chevy express 2500 with 4.8 sorry about that
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: i wrote the story already
JA: Anything else you think the mechanic should know?
Customer: swapped #1 coil still same issue
Submitted: 11 months ago.
Category: Chevy
Expert:  Roy replied 11 months ago.

good morning my name is ***** ***** I will assist

how did you determine it is number 1 cylinder??

have you checked the fuel pressure. low fuel pressure will set the 300 code as well as the lean code 171.

how were the injectors cleaned??? additives have little or no effect.


Customer: replied 11 months ago.
live data for engine misfire shows # 1 we didnt just use an additive we used top engine injector cleaner looks like loosing coil signal possible electric problem in wiring harness
Expert:  Roy replied 11 months ago.

ok, thanks. top engine cleaner does nothing to the injectors. is cleans the intake system, valves and the top of the pistons.

can you do a compression test on number 1??

did you check fuel pressure