I saw in another post (or maybe it was this one i dont remember) that your temps dropped almost in half after the cat, sounds to me like it is clogged. I know you have to have it to get inspected, but why not try cutting it off and welding in a piece of pipe to see if it helps?? If it does then you will know what is wrong, if not, just put the cat back in.

 

thats why she bought a new one

 

sounds to me like the mechanic doesn't have a clue. idle probably got higher because he tried to adjust it to mask the real problem. its imposible to diagnois a problem like this without seeing the truck, but the only thing i can think of that hasn't been mentioned is the air filter. replace the filter and make sure nothing is blocking the air inlet, there is a snorkel inside the fender that should be checked also, quick way would be to flip the air filter lid upside down and reinstall it to bypass the inlet pipe.

 

It does the same thing with the air filter off the truck idling. The idle speed has not been adjusted. On my tbi there is a metal piece covering the preset and he hasn't touched it. I had a high idle before I took it to him and he hasn't figured it out. It has gotten worse. He tried rewiring some grounds off the ecm and it did not help any. He will have to get it back and figure it out because I have tried everything and he says he has too but something is getting missed. He is going to check volume on the fuel supply he said.

 

On that air inlet in the fender how do you get to it? There is a plastic piece attached to the fender and air filter housing. Is there suppose to be air coming in that or out. That is where I am smelling a odor of fuel.

 

Did he do a compression test ? A leak down test ? Are you using the old cylender hesds, or new ones ?

 

if i remember right, its a brand new crate engine

 

Yes it is my second new engine. The last one had only 6,000 miles on it. GM goodwrench crate engine.(direct replacement engine) The engine is ruled out now. Looking for something else. How would I check that air inlet in the fender?

 

Anything new on this problem ?

 

Mechanic has me waiting because he has no room for the truck in his shop. I have been waiting for 2 weeks. I am just waiting on him now. I am not driving it and the tags have expired. As soon as I know something I will be posting on here the progress and hopefully the fix.