Need help!! I got Comptech headers, and Cat. Back exhaust and a Random Tech High Flow Cat. installed on 3 weeks ago and today I got a CEL!!! I took the advise and doubled up with 2 gaskets from the Cat. to the Cat. Back right from the beginning.

I haven't got the CEL read yet as its the weekend so I do not know the error but I have checked the gasoline cap to ensure its tight so it can't be that. I did notice that the exhaust coming out has a slight pulsating flow other than that the engine is running smooth, and drives fine.

Anyone doubled up on the gaskets from Cat. to Cat. back and still get a CEL??

 

If you have an Autozone near you, you can check the CEL for free. I have the comptech header and random hi flow cat as well. I have had no CEL's since installing the combo...it's been almost 3 months or so...maybe more.. i don't remember. However, I still have the stock exhaust, and I am not even using the double gasket method. I wonder why there are so many instances of CEL's with the random tech cat.

 

Check a scan tool theres a good possiblity they screwed up your 02 or air and fuel ratio sensor.

My was screwed up when i got headers isntalled, they fried and pretty much my car seemed to run fine, but on a dyno it was up and down as it was accelerating.

 

yea I am getting it scanned 2morrow. I really hope it isn't the 02 sensor, my mech. took extra care to ensure it didn't get damaged. Car was on a hoist so the sensor couldn't of hit the ground and he hung it up during the install.

is it safe to keep driving on it? Besides the light, car seems to run fine

 

got it scanned and it was a 0420 code. The O2 sensor that connects to the Cat. threw the code.

Dealer checked it though and found nothing wrong at all. They just reset it and said they would order a new O2 sensor if the CEL comes back on. Drove to work and so far its ok again.

 

what did the dealer say about all your mods?

 

It'll be back on within 2 weeks.

 

P0420 is a Catalyst deterioration code. Very common high mileage and/or aftermarket catalysts. More than likely changing the secondary O2 sensor will have no effect. Either put the stock catalyst back on, or try and get whomever you bought it from to replace it with a catalyst that works propery.

 

So you are suggesting that the hi flow cat may possibly be defective? I guess i have been lucky.. no CEL yet.

 

I think others on here have reported similar problems with these aftermarket catalysts.

The PCM compares the oxygen content readings between the primary and secondary o2 sensors to determine if the catalyst is working properly. In my experience, sometimes an aftermarket cat either doesn't last very long, or doesn't even work right out of the box.

 

Sorry to hear about all these CEL problems. I never did like the RT cat for the design, unknown quality and origin. Unfortunately, they are the only one that sells an aftermarket cat for the TSX.

 

What is wrong with the design? Just interested to hear your input.

As for use, I know RT is also a the provide for a GTO Header/Cat package and they seem to have had good luck with them.

 

High flow means less surface area for the cat to work with... Makes sense that a certain number of RT cats would have too high a porosity and thus not enough surface area to work effectively as a cat.

 

The rotating flange is fine except they didn't make a recessed area on the flange so the flared end wouldn't cause a gap when bolted up. I have never seen any aftermarket cat with so much leaking issues due to the flange connection. If they actually take the time to make the cat, there isn't any need for rotating flanges, because the alignment of all connections should be perfect and leak free. I'm sure anyone that has installed one of these would have noticed the less than perfect fitment. The pipe inside dia is even smaller than the stock cat. That's all.