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Ecm issues? I'm stumped

cliffmills

New Member
Joined
Jun 25, 2019
Messages
2
Hi all. I searched bit couldn't find anything that matches my issue. 2008 avalanche 5.3. Have had lots of sea codes happening. Here's what I've replaced. Water pump, fans, radiator, t-stat, temp sensor, exhaust manifolds, gaskets, entire exhaust to include O2 sensors, mass air flow sensor,map sensor, purge selonoid, juel pump, plugs, wires, fuel injectors, coil packs, intake gaskets,oil pressure sensor. All OEM or quality parts store parts. No cheap eBay crap except for two refurbished ecms.
Here is where I stand now:

1st ecm (original) gives codes p0175 and p0172..no misfire p0307

2nd ecm (refurbished)eventually gave p0307 and would not finish last ecm test

3rd ecm (refurbished) ..
Drove about 60 miles and turned around and came back home. Wasn't until halfway back that it gave a pending p0307, then changed to pending p0300. Never an engine light came on. And, it didn't complete not one single ecm test the whole trip. And, I made it there and back on less than a quarter tank.

Any thoughts?
 
My guess is AFM issue and lifters for #7 cylinder gone bad

Search AFM + LIFTER
 
I Agree with the AFM lifter hypothesis. I rebuilt the top half of my engine after I started getting codes on my scanner. Everything works great now.
 
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