jedimaster71472

OK, so I bought a code reader for my cars and on the 97 Formula I keep getting P0420, which trips the engine light. I have longtubes on the car. It's for bank 1 and is listed as 02 sensor (heated 02 sensor comes up fine). Am I correct in assuming that the heated 02 sensor is the one before the cats and that the plain 92 sensor is after?

I'd like to get 02 sims for after the cat. I know it's related to cat inefficiency due to the headers relocating the cat, but I'm not worried about proper functioning of the cat. I just want the engine light off so I can get the car inspected.

So I guess what I'm asking is am I on the right track in replacing the 02 sensor after the cat and can someone recommend a place to get the proper sim for my LT1?

Also, does anyone have a pic of what I'll be working on? I'm finding pix of a single cat exhaust but not the one I have with dual cats. The cat looks, I believe, somewhat like an exhaust resonator and is round, not like the one under the car that makes the hump in the passengers side floor. I found this pic, of the heated sensors, which makes me think they are the ones before the cat:

Thanks in advance.

jedimaster71472

Alright- just had the car looked at for the engine light issue- couldn't figure out if it was due to the 02 sensors or the cats. I was quoted 2500 dollars to replace both cats- can someone tell me what a realistic estimate is?

Yes, I'll be looking into eliminating them.

jedimaster71472

I went with Magnaflow direct fit high flow cats- they just came in yesterday, but the driver's side has no 02 sensor bung? http://www.jegs.com/i/Magnaflow/642/23517/10002/-1 Weird, because the one for the passenger's side has one in it. I can't imagine it will be a big deal to weld a bung in at the shop when they install them.

jedimaster71472