which is better to use when upgrading the factory up-pipe to one w/o a cat. I know if the egt is not used a CEL will occur but has any one used one while including or retain the egt sensor. is there a difference in how the car will run w/o the sensor.

 

Some say the egt will get messed up because of heat soak because there's no cat, but from personal experience I removed it and have not had a problem with it. Just remove it, plug up the hole on the aftermarket up-pipe and install the 2.2 KOHMS .5 watt resistor.

 

what if the aftermarket does'nt come w/ a egt bung, like the hks up-pipe,also where can i get that resistor your talking about.

 

Radio Shack or Fry's or other local electronics store.

2.2k Ohm resistor

they cost next to nothing.

 

Uppipe CEL fix how-to, although there are slightly easier and cleaner ways to implement this fix. Relatively easy mod.

I've had the resistor in for 20,000 miles with no re-occurrence of the CEL since ECU reset.

EDIT: If I had to buy another uppipe, it would be without the EGT bung. One less sensor to go bad or having to replace. The lack of an EGT sensor does not affect how the car runs as long as you have the resistor CEL fix in place. The purpose of the EGT sensor is to monitor the condition of the uppipe catalytic converter.

--
0==WW==0
"…axles of evil…" - george w. bush

 

kinda off topic but would an aftermarket egt sensor read accurately in the up pipe bung?

 

It will read accurately but a preferred area among members and installers seems to be in the exhaust manifold adjacent to cylinder #3 because this is the cylinder that tends to run lean, therefore hotter. Measuring at the uppipe will average out the reading from all four cylinders which wouldn't be a problem if they always operated at the same temperature.

--
0==WW==0
"…axles of evil…" - george w. bush

 

extending this question a bit more, so to use a hks downpipe would i need to mess with the o2 sensor wiring by using the CEL fix for that too. two o2 and one egt if im correct. the o2 in the up-pipe is fine as is, the egt in the up-pipe needs resistor trick to prevent the CEL, the downpipe needs o2 simulator to fix. Please correct me if im wrong.

 

The factory uppipe does not have an 02 sensor. It has only an EGT sensor (at least for '02) which needs only the resistor CEL fix.

An aftermarket downpipe will likely need some sort of CEL fix for the 02 sensor.

--
0==WW==0
"…axles of evil…" - george w. bush

 

i noticed that the cobb tuning up-pipe has both bungs. the picture im assuming is for the newer wrx then....? what about the CEL fix that moves the EGT or O2 sensor away from the flow of exhaust. Not positive which this fix is for EGT or O2. any help