Ok, its late and i tried searching for this on the site cuz im sure its covered but i just couldnt find it. Ever since ive installed my SSA headers i throw a CEL randomly. I hook up the OBDII comp and it tells me its the main efficiency TWC bank 1...so im guessing thats the first 02 sensor thats in the headers right? Well, i clea the codes everytime it comes on...in hopes its not a broken sensor. But NOW it comes on all the time, even after i reset the computer or clear the codes. Is it just a bunk sensor or do you guys know what might be wrong? Greatly appreciate some help, sorry i wrote a whole friggin book here. Good night.

 

this should be in newbie section, but i'll be nice and answer ya.

your o2 sensors, 1st and second reading the same thing because 1st cat was taken out, so it's throwing CEL out. you gonna have to weld a bund behind a cat and relocated your second sensor. do more research and u will find lots of info on this!

 

yes, your o2 sensors need to read the differences between pre-cat and after cat...

 

Ok thats what i figured...guess ill need to get a cat then...i have no cats at the moment... so if i get a second cat where i have the SSA "highflow" cat lol and put the second one behind it im good to go?

 

"second one" you refering o2 sensor?
then, yes!

 

ok then, do those 02 sensors pick up heat also, or could i be tricky and just put it outside of the exhaust so it gets a theoretically "cleaner" reading?

 

yes, they depend on heat as well, that's why most likely you will be getting CEL every other time, maybe 300-500 miles. It has to be placed at the certain distance from the cat and 1/4 of an inch will throw CEL eventually.

 

ok thats what i thought, guess ill just have to buy a cat and reweld then. Thanks

 

np, btw get a high flow cat, catco preferably

 

so if you get racing headers, will you need to modify your 02 sensors depending on the headers? does a catback exhaust come with a racing cat? do aftermarket cats pass emissions?...or am i totally off. lol.

man... tweak your car one bit and the CEL alarm will go off!!! you're caught red handed...