Joshcivic00

the shop i took my car too put two new o2 sensors on my civic because i was having turbo problems(as many know).anyway my stock cat and cat o2 senor was fried. he put the stock o2 sensor in the catco highflo cat and strapped the new one outside the cat.could this cause problems and is it better to leave the the o2 sensor in the cat(although its high flo).

Jafro

Strapped it outside the cat? Is it threaded into your exhaust? I'm not following your description.

Q: Is the sensor not physically installed in the cat?

Q: If so, did he plug up the bung for it?

2¢: If you have a high flow cat, and it still contains its catalyst (and works) then there's no reason not to install the o2 sensor in your cat's bung (that's going to be someone's sig quote, I know it). All the second o2 sensor does is check to see if your catalytic converter is installed and working. It actually has nothing to do with adjusting your ECU's fuel trims like the 1st one does. It will throw codes if it doesn't smell exhaust. It will throw codes if it smells too much exhaust. Basically, it just needs to be in the cat or behind it and you shouldn't have any trouble unless the cat is so far from the engine that it doesn't light off.

Joshcivic00

my old sensor that isnt connected to the ecu is plugged in the high flow cat, the new sensor is strapped outside!I wonder if this could explain why my ecu is saying i am having an "fuel system malfunction:too lean or too rich",it did it before the i had the high flow cat but i was also running extremly rich because E-manage wasnt hooked up correctly.if this isnt why it will eliminate this possibility!

thanks