Haddixj

iTrader: (1)

I have an 01 SS I bought for my wife and it has P0420 code I replaced the rear O2 with a denso sensor. We had it smogged and on the dyno the hydrocarbons were fine 10-15 so I dont think its the cat. Someone suggested tuning out the rear o2 sensor will the car still pass the computer functional test? The car passed everything except that because the monitors were not ready because I erased the code to see if it would clear.
Thanks
Jason

Haddixj

iTrader: (1)

Anybody? Who is a good shop to get a tune from in Sacramento California?

cj92345

iTrader: (2)

i believe you need the cat monitor to run and see what happens

Haddixj

iTrader: (1)

who makes a good scanner to be able to see O2's function? I have just a normal one that views the codes but I know there are some that will show you live O2 data. I dont want to replace the CAT just to see if it will fix it

cj92345

iTrader: (2)

i have not seen a p0420 fixed with o2 sensor, cat is worn or weak, it may take awhile to set the po420 again, if it's just weak, i would watch the cat monitor and as soon as it runs go right to the smog shop, thats if it does not set another code, i've seen cat codes take a long time to set after being cleared, depends how worn the cat is.

Haddixj

iTrader: (1)

It will reset the code after about 30 or so miles it has done it 3 times so far, I may just replace the CAT, I dont know what the difference is between 49 aand 50 state cats except price. I have never noticed them checking under the car for them in the past

mannyman84

iTrader: (2)

If you got a p0420 replace bank one cat. P0420 doesn't mean the o2 is bad but it's telling you that the rear o2 sensor detected that the bank one cat is bad. If it was the o2 you would of got an o2 code. And if you get it tuned out it won't pass because it has a monitor that needs to be set.

Haddixj

iTrader: (1)

Thanks that is what I guess I will try, I have just never had to replace a CAT when the HC are below the limit, usually it fails on the dyno not on the function test.

Haddixj

iTrader: (1)

Also what is the difference with 50 state and 49 state models? will it fail smog and how do they even know? I can get it shipped to a friends house and he can ship it to me