I don't know if I have this in the right forum or if this should be in exhaust, but I finally have the new engine running and everything seemed just fine until I hooked up the Y-Pipe to the cat. Before hooking that up, I was running the car with just the headers and y-pipe and checking out the new install. Everything was great, better than I had hoped for. I needed to get a sleeve to connect the 3" Y-Pipe to the 3" Cat. I had one made which is also 3" pipe but the ends were expanded so it would slip over the end of the cat as well as slip over the end of the Y-Pipe. Oh, I am using Hooker Headers 2055's. After hooking all that up, the car now seems to be bogged down.

I rebuilt the engine because there was a cracked head and radiator fluid had got all in the oil and it was smoking white so badly that you couldn't even see the car at a stoplight. Anyway, my question is, is it possible that the cat is shot since there was so much fluid in exhaust? Is it really possible that this is what is causing it to bog down and cause a knocking or like a popping sound or does it seem like it's something I need to check out with the engine? I guess the best bet is to remove that sleeve and see if it returns back to normal?

My build-up is a 350 bored 60 over, ZZ4 cam, stock GM roller lifters, Comp Cams pro mag roller rockers 1.5 ratio, 113 aluminum heads, flat top hypereutectic pistons, stock rotating assembly, Hooker 2055 headers and Y-Pipe coated by Jet Hot with their sterling coating.

Does anyone have any ideas?

Thanks,

Pat

 

Anyone have any ideas or suggestions?

Thanks,

Pat

 

I would get a piece of 3in the size of your cat and see what happens

 

Well, I have often thought about deleting the cat, but I would like to keep it legal on emissions if I ever move to a state which requires it. It really seems likely that the cat could be causing this, but I would really like to make sure first.

Thanks for the suggestions, I do appreciate it! Any other thoughts??

Pat

 

When the engine is running does the cat get cherry red?

 

No, the cat didn't get hot like that, but the engine definitely didn't run properly -- seemed bogged down, after hooking the cat back up. I know the muffler is bad and will be replacing it this weekend.

When the exhaust was running as open headers (just the y-pipe hooked up), it ran tremendous. After hooking the cat up, I had a little popping and like I said it seemed bogged down.

Thanks,

Pat