She threw a code: P0430

[GoHard]

I have brand new headers and catted Y from arh. Got it dyno tuned and now 75 miles later I get this code.

I should also mention my car has been killing me on the gas mileage since I bought it which is why I just modded it and tuned in hopes that was another way to fix the problem. (14 mpg in the city driving like ms daisy!)

When Steve tuned it he said the 02's were switching fine. I got the catted Y so the exhaust will still sound good through the lm2 so I just kept all 4 02's anyway.

Also, and this has been a pain to figure out but if I'm anywhere in 1500-2000 in any gear and I give it say even 1/4 throttle I got this rattling that sounds like whistling- almost like a FI car would sound. Any ideas what that could be or if it is a bad cat???

[Fbomb]

aftermarket cats are probably hi-flow so they aren't as "efficient" as the stockers. Might as well have just tuned out the aftercat O2's. The sound might be an exhaust leak. Is the Y-pipe slip fit onto the headers? I have a small leak there, have to seal it with some foil tape...

[GoHard]

Yeah the Y is a slip fit. Everything was bolted together. I also found this on ls1tech could it be the same problem with my car?

http://www.ls1tech.com/forums/genera...r-removal.html

[Fbomb]

Kinda doubt it but you could have your air pump tuned out and then just put a quarter in between the tubes in the headers and the air tubes. Over time the weight of the block-off kits will vibrate the air tube right off the header so it's better to leave the hose there.

[meissen]

P0430 means your downstream o2s are thinking your cat is bad. If it's a new high-flow cat, I would get o2 simulators for the rear o2s or just tune them out entirely.

[OIF1VET]

Mine are just tuned out(rear 02's).. For you AIR on the headers, I put the block out plates on with the ends of the airtubes over them to make sure they stay sealed. No problems in 4 years. You just cut the part of the AIR tube that bolts to the header off the tube.. No sense having the tubes if they do nothing...

[Derek]

Kinda doubt it but you could have your air pump tuned out and then just put a quarter in between the tubes in the headers and the air tubes. Over time the weight of the block-off kits will vibrate the air tube right off the header so it's better to leave the hose there.

bingo, mine just fell off a couple weeks ago, I found a bolt to tap in the hole where the tube broke off.

[Fbomb]

Yeah unfortunately I don't have a tig welder so my air tubes are staying in place, air pump is disabled so they're just for looks.

[GoHard]

I have offroad headers so no AIR fittings. I just filled up again and out of a full tank and all city driving, not a SINGLE wot run I got 14mpg. I think Steve messed up my tune lol jk JK but the tune is good and everything else seems right (no exhaust leak either). I think I'm going to take a good trip on the highway and see what I average then. Other than that I'm totally lost at this point lol.