Thread: Best cat to use with Speed Daddy headers?

Hey guys, I'm having the hardest time trying to passs emissions ever since I installed speed daddy headers. I got my uncle's shop to weld on some generic cat after installing the headers and no matter what I can't pass emissions. I've got the o2 codes tuned out, but my emissions readiness still says the catalyst is still incomplete. Any recommendations for a good quality cat would be appreciated!

if it's a 2001 or later, you have to find a way to disable the cat test diagnostic

http://imgur.com/SyzpJvA Here's a pic of my Emissions Readiness s/DTC.

Honestly I never checked my emissions readiness with my old pcm. Wish I had now lol. I can understand that the cat would take a little while to show its ready, but any idea why the o2 wouldnt ready by this point? After 230 miles I'm sort of losing hope that it'll fix itself with more miles. I'll go give it another try later on tonight and see if anything changes, but I won't hold my breath.

And thanks, you're the man.

Also heres a look at my o2 sensor voltages http://imgur.com/RnQnNer. They fluctuated as I drove, within .05 or so. As far as I know they look fine, but figured I'd present that information. Also here a some vehicle test results http://imgur.com/CqoyXhn. The code TID: $05 CID:$0a was not working properly, infact it was the only code that wasnt working properly. Its the rich to lean sensor switch and it hasnt calculated anything at all. Any ideas on what might be the cause? I'm thinking this is maybe one of the reasons why o2 wont show its ready yet. But I havent got a clue. If theres any more information needed I can try to provide more.

Originally Posted by Scottydoggs

the up stream o2 should be dancing up and down with its volts, .1 to .8 over and over and over. pretty sure thats your switching time. so you might need a new o2. is this the stock o2 your still using?

I'll go take a look and see if it fluctuates like you said. And yes it's a stock sensor, so its likely due for replacement. I'll order one from rock auto and keep you guys updated.

Sorry I was mistaken about the whole o2 voltages. The upstream and downstream o2s both fluctuated based on how much gas I gave it. I seen values as low as .2 to values as high as .9. So I'm not confident that these are my problem, but the new o2 is on its way.

So I've put a few hundred miles on the car after the new o2 install and still my o2 and car say they're not ready. So now I'm convinced this something that throwing parts at just won't fix. Scotty, you think you can check my pcm out and see if there's anything funky going on? If not, then I'm about ready to just call this car a lost cost and move on.