Convertor opinions?/ help

[ohio4runnerjoe]

So have a 99 T4R with cali emissions, well I blew out the gasket between the two convertors this weekend and the check engine light went out. It was reading p0420 catalyst efficiency below threshold. Well decided to pull the convertor and check it out with a flash light for clog and or cracks. Found a little bit of a clog but really not bad but did find a crack in the piping by the hanger. So started it back up let it run with the open exhaust and the rear o2 sensor unplugged. Surprisingly no check engine light came back on. So question, make a test pipe and leave the o2 out or buy the 2 magnaflow convertors and new o2's?

 

[TheDurk]

So have a 99 T4R with cali emissions, well I blew out the gasket between the two convertors this weekend and the check engine light went out. It was reading p0420 catalyst efficiency below threshold. Well decided to pull the convertor and check it out with a flash light for clog and or cracks. Found a little bit of a clog but really not bad but did find a crack in the piping by the hanger. So started it back up let it run with the open exhaust and the rear o2 sensor unplugged. Surprisingly no check engine light came back on. So question, make a test pipe and leave the o2 out or buy the 2 magnaflow convertors and new o2's?

Just to note that the Cat Efficiency test is 2-trip detection and the requirements for a 'qualifying' trip are quite specific. So it is NOT surprising no code was set. Within a tank of gas, it will set a P0420, trust me. A P0141 and P0136 for the unplugged sensor will hit even faster, but they are also 2-trip detection.

The answer to the pipe or cat question is a simple cost vs. noise and pollution trade-off, plus the annoying CEL factor. Why replace both cats if only one is cracked?

 

[ohio4runnerjoe]

Just to note that the Cat Efficiency test is 2-trip detection and the requirements for a 'qualifying' trip are quite specific. So it is NOT surprising no code was set. Within a tank of gas, it will set a P0420, trust me. A P0141 and P0136 for the unplugged sensor will hit even faster, but they are also 2-trip detection.

The answer to the pipe or cat question is a simple cost vs. noise and pollution trade-off, plus the annoying CEL factor. Why replace both cats if only one is cracked?

Well I figured at some point the cell would come back on but I was just surprised that it didn't even with letting it run for about 25 mins. Like I said it was throwing the p0420 cell before the gasket blew out and then turned off when it was broke. Just thought at least it would throw heater circuit malfunction code for the rear sensor not even being there.

As for the test pipe/ or new convertor question. I'm not to worried about the noise since I'm running a borla catback on it now and is kinda loud so a little more shouldn't bother me. We don't have emissions test here so not to worried about an e-check either. May main concern was with how it will run and will I do any damage with not having a rear cat or an o2 sensor back there. As far as replacing both cats with new ones I figure if I'm going to do one I might as well change them both and put new o2s in with them. Thanks in advance

 

[TheDurk]

Well I figured at some point the cell would come back on but I was just surprised that it didn't even with letting it run for about 25 mins. Like I said it was throwing the p0420 cell before the gasket blew out and then turned off when it was broke. Just thought at least it would throw heater circuit malfunction code for the rear sensor not even being there.

As for the test pipe/ or new convertor question. I'm not to worried about the noise since I'm running a borla catback on it now and is kinda loud so a little more shouldn't bother me. We don't have emissions test here so not to worried about an e-check either. May main concern was with how it will run and will I do any damage with not having a rear cat or an o2 sensor back there. As far as replacing both cats with new ones I figure if I'm going to do one I might as well change them both and put new o2s in with them. Thanks in advance

No damage other than the environment. Just the CEL factor. A simulator can solve that.

 

[ohio4runnerjoe]

No damage other than the environment. Just the CEL factor. A simulator can solve that.

Ok awesome, thank you for all your help. I don't like hurting the environment, but its hurting my wallet thinking about cats! I will def plant a few trees this year for it. And I think I'm going to try and make my own simulator for it also. Thanks again.

 

[jgue467]

... I was just surprised that it didn't even with letting it run for about 25 mins. Like I said it was throwing the p0420 cell before the gasket blew out and then turned off when it was broke. Just thought at least it would throw heater circuit malfunction code for the rear sensor not even being there.

I forget the specific parameters but it I think it requires 50+mph driving for like 30 minutes straight the code, then repeat hence the 2 trip notion.... :banana: