The cars runs fine, so I don't think they are clogged up. I bought some o2 simulators to go behind the converters from Summit, and they're working so far. Has anyone used them?

 

i've got a 96 Z and i just had to use some simulators to pass smog on friday. you'll need to clear any codes you've got in the computer (assuming thats why you bought the sims) and then hook up the simms. They immediately solved the problems i was having so i was happy with them.

 

Then why did you put 02 sims in? they will not fix a problem with the cats. They are just there to help not set a check engine light when you gut, remove, or buy high flow cats. if there is still a problem with teh cat or front 02 it will continue to be an issue

 

I installed the sims because the only problem with the cats is that they are letting too many fumes through, and thus kicking on the SES light. For OE replacement cats, my local GM garage wanted 400 and something a piece. This was my least expensive option. Guess I could take them clear off, make them strightpipe. I have had problem with exhaust rattling in the past, after being messed with. (I know it don't happen everytime)