pushkarvaidya

I have a 2006 Scion TC with 165K miles on it. Just bought it 6 months ago.
Now I get a cat con efficiency code. I had it reset once by Meinike but now its back, so I am guessing i have to put a new cat con.

Being tight on budget, I am planning to do the repair at home if possible. Hence all questions are targetted with that in mind

1. I took a look at the cat con on the exhaust manifold between the motor and the radiator. I also see a O2 sensor before and after that catcon.
Is that the only catcon in the car? Some mechanic told me that there are two cat cons and its hard to tell which one is bad.

2. It seems fairly straight forward to replace that section of the exhaust pipe. I change my oil regularly but have not done a major job at home. Does anyone have any experience or any tips to do that (or not do that) at home?

Thanks

TBurrr

As far as replacing the one you mentioned your correct it is very easy should take 10 minutes if that 5(maybe 6) nuts to undo the exhaust from the engine 2 bolts underneath to remove it from the rest of the exhaust and unscrew the o2 sensor and done old ones out new one goes in.

Tips: get an o2 sensor socket not necessary but makes it easier i think u can rent them from an auto parts store

and when putting the bottom two bolts back in spray a little lube on the threads first i got impatient once due to some rust and stripped the threads

Basebllstar

Chances are the problem is in your primary CAT in you header. There is and O2 sensor before and after this CAT. There is no sensor after the CAT in the midpipe, so even if your secondary CAT was bad, your car has no way of knowing. I have a 2006 tC and my CAT started to die around 100k miles. You have a few options on what you can do, unfortunately, most of them are expensive. It could be a bad O2 sensor, I doubt it. You'll probrably need to replace the header, either OEM (expensive as ____), aftermarket (also expensive), or try and find a used oem header. If you were looking for a really easy quick cheap fix, look into an antifouler for your secondary O2 sensor; i don't reccomend this. Remember the cheap fix isn't always best.