NervGS
10-10-2006, 09:09 PM
Hi all,
Before I say anything, yes, I've posted on Club4ag already and would just like to get anyone's pov from here on it...
I have a Corolla with a 20valve 4AG, using a TRD 4-2-1 headers and could not pass smog with it (big surprise there). My previous Corolla also had the same setup, but used a 4-1 header and managed to pass smog with a bit of trickery here and there... Both had/have brand new cats on them. The car at the moment runs extremely rich and backfires almost whenever I lift throttle. The previous car would backfire mostly at high RPMs or, whenever I'd tap the gas very slightly, but never when I lift at low RPMs (like what the current setup is doing). Also, the exhaust fumes smells like it has no cat on it (I forget how the previous car smells).
My question is, the current header (4-2-1) setup has the o2 sensor in one of the dual runners where as the 4-1 header has it in the collector, can this be causing it to rich and have it smell (and to ultimatly fail)? I'm also thinking it could be a faulty o2 sensor as well (but wouldn't the car run like crap?)... In a nutshell, my smog tech told me to relocate the o2 sensor from the dual runner to the collector and it should help whereas my mom's mechanic told me it wouldn't help as much...
Any input is appreciated.
Thanks!
-glenn
Before I say anything, yes, I've posted on Club4ag already and would just like to get anyone's pov from here on it...
I have a Corolla with a 20valve 4AG, using a TRD 4-2-1 headers and could not pass smog with it (big surprise there). My previous Corolla also had the same setup, but used a 4-1 header and managed to pass smog with a bit of trickery here and there... Both had/have brand new cats on them. The car at the moment runs extremely rich and backfires almost whenever I lift throttle. The previous car would backfire mostly at high RPMs or, whenever I'd tap the gas very slightly, but never when I lift at low RPMs (like what the current setup is doing). Also, the exhaust fumes smells like it has no cat on it (I forget how the previous car smells).
My question is, the current header (4-2-1) setup has the o2 sensor in one of the dual runners where as the 4-1 header has it in the collector, can this be causing it to rich and have it smell (and to ultimatly fail)? I'm also thinking it could be a faulty o2 sensor as well (but wouldn't the car run like crap?)... In a nutshell, my smog tech told me to relocate the o2 sensor from the dual runner to the collector and it should help whereas my mom's mechanic told me it wouldn't help as much...
Any input is appreciated.
Thanks!
-glenn