Not only flexpipe was rotted, but so was the cat
Thread Starter
What does that mean?
Joined: Apr 2007
Posts: 392
From: Calgary, AB
Not only flexpipe was rotted, but so was the cat
So the muffler shop cut out my cat and replaced it with straight pipe, but also drilled a hole for the rear o2 sensor. Is this going to cause me any issues?
Member
Joined: May 2017
Posts: 131
From: Los Angeles
I would guess you'd get a CEL light and code for a failed cat. The only job of the rear o2 sensors is to monitor the condition of the cat, and now you don't have one, so it will indicate a problem.
But it shouldn't make any difference in actually running and operating the vehicle.
But it shouldn't make any difference in actually running and operating the vehicle.
Thread Starter
What does that mean?
Joined: Apr 2007
Posts: 392
From: Calgary, AB
I would guess you'd get a CEL light and code for a failed cat. The only job of the rear o2 sensors is to monitor the condition of the cat, and now you don't have one, so it will indicate a problem.
But it shouldn't make any difference in actually running and operating the vehicle.
But it shouldn't make any difference in actually running and operating the vehicle.
Thread Starter
What does that mean?
Joined: Apr 2007
Posts: 392
From: Calgary, AB
Senior Member
Joined: Oct 2012
Posts: 2,974
From: Portland, Oregon
As far as I know, the front oxygen sensors do the work of setting the fuel adjustment. So that the car runs well, but does not pollute too much.
The cat is supposed to clean what's left.
The rear oxy sensor is there to determine if there is less pollution after it leaves the cat than enters it.
An anti fouler would make the rear sensor sense less pollution than reality. So it would tell the computer that all is well, no cel.
Do consider that there are laws against doing this kind of thing.
The cat is supposed to clean what's left.
The rear oxy sensor is there to determine if there is less pollution after it leaves the cat than enters it.
An anti fouler would make the rear sensor sense less pollution than reality. So it would tell the computer that all is well, no cel.
Do consider that there are laws against doing this kind of thing.
Thread Starter
What does that mean?
Joined: Apr 2007
Posts: 392
From: Calgary, AB
As far as I know, the front oxygen sensors do the work of setting the fuel adjustment. So that the car runs well, but does not pollute too much.
The cat is supposed to clean what's left.
The rear oxy sensor is there to determine if there is less pollution after it leaves the cat than enters it.
An anti fouler would make the rear sensor sense less pollution than reality. So it would tell the computer that all is well, no cel.
Do consider that there are laws against doing this kind of thing.
The cat is supposed to clean what's left.
The rear oxy sensor is there to determine if there is less pollution after it leaves the cat than enters it.
An anti fouler would make the rear sensor sense less pollution than reality. So it would tell the computer that all is well, no cel.
Do consider that there are laws against doing this kind of thing.
Thread Starter
What does that mean?
Joined: Apr 2007
Posts: 392
From: Calgary, AB
I've decided that when it comes to exhaust matters I'm out of the DIY zone, so if I have to take it back to the shop to install an anti fouling part, instead I will just get them to put a new cat in. So far after driving 30 mins the CEL has remained off. We'll see how long that lasts.
Member
Joined: Jun 2015
Posts: 160
I have read in older posts that without the rear cat you will get a gas smell. Have you experienced this? Or a rotten egg smell?
I deleted my front precats with a new Y pipe but added a new rear cat a year before because it came with a striped O2 sensor bung hole. No check engine and has passed emissions well within range.
I deleted my front precats with a new Y pipe but added a new rear cat a year before because it came with a striped O2 sensor bung hole. No check engine and has passed emissions well within range.
Thread Starter
What does that mean?
Joined: Apr 2007
Posts: 392
From: Calgary, AB
I have read in older posts that without the rear cat you will get a gas smell. Have you experienced this? Or a rotten egg smell?
I deleted my front precats with a new Y pipe but added a new rear cat a year before because it came with a striped O2 sensor bung hole. No check engine and has passed emissions well within range.
I deleted my front precats with a new Y pipe but added a new rear cat a year before because it came with a striped O2 sensor bung hole. No check engine and has passed emissions well within range.
6 months later no codes, makes me wonder if they put in an anti fouling without me knowing. Anyway I'm going to fix it soon. Any suggestions for a RockAuto-sourced cat which is close to OEM as far as sound levels? Same with a muffler? I do a lot of driving and I find noisy exhaust to be irritating after a while so I'm looking to get the car close to factory as far as noise levels.
As far as I can tell I'm in the same situation that you're in and my local mechanic has replaced the rusted out catalytic converter with straight pipes. My front two oxygen sensors are failing and the rear oxygen sensor after the cat (straight pipe) is working properly however no codes for any oxygen sensors or for catalyst efficiency.
Maybe these old ECUs are super leniant?
Idk. But no codes in 5 months in this 98 maxima GXE.
If This Were my 2000 Maxima I know for sure I would have codes as soon as the oxygen sensors or cats begin to fail
Thread Starter
What does that mean?
Joined: Apr 2007
Posts: 392
From: Calgary, AB
As far as I can tell I'm in the same situation that you're in and my local mechanic has replaced the rusted out catalytic converter with straight pipes. My front two oxygen sensors are failing and the rear oxygen sensor after the cat (straight pipe) is working properly however no codes for any oxygen sensors or for catalyst efficiency.
Maybe these old ECUs are super leniant?
Idk. But no codes in 5 months in this 98 maxima GXE.
If This Were my 2000 Maxima I know for sure I would have codes as soon as the oxygen sensors or cats begin to fail
Maybe these old ECUs are super leniant?
Idk. But no codes in 5 months in this 98 maxima GXE.
If This Were my 2000 Maxima I know for sure I would have codes as soon as the oxygen sensors or cats begin to fail