If the RPMs are going up (above 3K?), But not your vehicle speed, then you have trans issues. If you can't get your RPMs to go up, then you have engine issues.

Because of the past cat problems, I'm still thinking along those lines (IF you can't get any higher RPMs out of it). Perhaps a piece of the cat internals worked it's way into the muffler and is partially clogging the system there? If you CAN get RPMs out of it, then it's likely a trans problem; 4 quarts low is pretty significant.

 

Trans oil is where it should be. code po300 random misfires. hmmmmm

 

soo doesnt this sound like the head issue? could it be anything else? Just wondering if anyone had dealt with this. seems I will most likely have to take it to a dealership.

 

figured someone here might have had a similar issue.

 

This might be a transmission issue. is $1200 shipped a good deal for a rebuilt upgraded performance transmission? how much should i pay for an install?


Could this be a cylinder head issue causing this too?

 

getting ready to take the vehicle this week , just really wish someone could have chimed in .

 

ok. so the ngk iridiums werent that old..but i pulled them and all5 were cracked..have put in the oem ac delco iridiums and then the vehicle wouldnt start..got it to start and it said multiple cylinder misfire.

i still had 4 out of the 5 original oem spark plugs in the garage...same ac delco model and all. put those 4 in..it cranked..and now it says cylinder misfire on 3.

so cylinder 1,2,4 have old ac delco spark plugs..and cylinder 3 and 5 have brand new ac delco spark plugs. doesnt make sense to me that it didnt work with all new plugs.
adding the new one to cylinder 3...truck runs smooth and no misfires

Does this make sense to anyone?

 

Sure, it makes sense. You apparently are not very good at changing plugs. You have to put the coil on plug pack straight, snapped all the way down, firmly connected before you secure it in place with bolt. If they are crooked, not on all the way, not connected properly, you will have the issues you are describing.

 

truck was taken friday to a transmission shop. Will find out Monday what's going on.

 

Yep. Transmission issue. no 3rd gear.