I forgot I already started this post and started a new one (Remember I'm OLD!). But here is all the info I thought needed to be included.
My '07 Tahoe lost two cylinders. I had the DOD deleted 150XXX ago and it has a cat back and CAI. I found an aluminum block AFM deleted engine with ~114K on it. The engine has an AMS Racing cam and lifters in it. I had a guy install it for me (I've had a heart attack and a stent and am now over 70.). Engine runs good, sounds great with my new cat back (The old one was about rusted out.), but the "check engine light is on and the "service stabilitrac" light comes on. The only other things done were I had new plugs/wires and a set of cheap Amazon injectors installed.
I had a local shop check it out. The shop was po'ed that I didn't pay them thousands to replace the engine and was kinda snarky. After $145 all I got out of them was that it is throwing PO3, PO175 and PO172 codes. They said that, since they didn't put the engine in that they could do no more. They put on the diagnoses that they suspect it "may have wrong engine and or/ components".
The original engine started having an intermittent misfire and then suddenly dropped two cylinders. I assumed that meant that a couple of the DOD lifters had failed. So, this engine came up for sale at the same time and I pounced on it cause I could buy it for what a delete kit would cost me. When the guy put the engine in and started to spin it over to prime the new Melling oil pump, it wouldn't build pressure. He pulled the oil pan and found they had cracked the oil pickup tube. We used the tube off the old engine and it has worked fine. My guy suspects that's why they sold the engine because they couldn't figure why there was no oil pressure.
I haven't pulled my old engine apart (Heart attack.) to see if it was just the lifters. I drove the old engine about 30 miles on 6 cylinders to have the engine replaced. The "check engine" light and "service stabilitrac" lights came on then. I didn't question that since it was only running on six cylinders. But now it still has the lights on and, after I run about 10 miles, the "service stabilitrac" will come on.
Any help from anybody?