Ok so i take my car into the dealership today to get a CEL code pulled. All i have done is a cusco dp, fujitsubo legalis super R exh, and an jdm sti up-pipe. THey pull the code and tell me that the egt sensor on the upipe is malfunctioning and that since i have an afermarket up-pipe that its not covered under the factory warranty. I have no problem with this, but i do have a problem with their explanation. The service manager said that because of the removal of the cat, the heat from the engine is messing with the EGT sensor. Heres my question though. Since the sti doesnt have a cat on the up-pipe and they run hotter and put more power out than a regular WRX why dont they have problems with their egt sensor? When i asked them this all i got was a balnk stare.
So now i have to figure out what to do so im asking you guys. The dealer suggested having my dp tapped and relocate the egt sensor but i dont think thats the answer. Im not really sure how important this sensor is, so if you guys have any suggestions please let me know. I dont feel like paying the dealer $400+ to get this done. Also i plan on getting either the UTEC or ECUTEK so if i get these will they take care of the problem?

 

LOL. The service manager has been smoking the glass pipe too much. Catless=LESS heat not more.

 

i know but i figured it was a lost cause trying to explain that to him.

 

you know the sti dosent have an egt probe in the up pipe

 

Burned out EGT probes is a known problem with catless uppipes. That's why most tuners who sell them recommend using the resistor mod and putting a bolt in the uppipe.

Lurk, how do you figure that removing the cat lowers your EGTs? Yes, the cat gets heat soaked when it's there, but it doesn't magically create more heat. Having the cat in place smooths out fluctuations in EGTs, so while your average reading may increase, by heating the exhuast gas when it's lower coming from the ports, it actually lowers peak EGTs at the sensor. So, you may see lower average EGTs with no cat at the sensor, but peak temps will actually be higher.

Gearhead is correct, the STi has no EGT sensor. The sole purpose of that sensor is to monitor the catalytic converter in the uppipe on a WRX.

 

you went in to get a CEL pulled when you removed 2 cats?

 

I guess you can't imagine not being scared of a Subaru dealership?

jason

 

I know the CEL was because of the dp, but since it was under warranty i figured id get it checked out and make sure nothing else was wrong with it.

 

Ban, cats do actually get hotter but its not much of a temperature increase. My organic chem profesor was talking about this. He was saying that the precious metals and other items located in a cat act as catalysts that end up reducing the hydrocarbons and CO and CO2 in the exhaust gasses. When you reduce a substance it requires more energy and this creates heat. Thats what he said at least.

 

err i thought they reduced the CO and increased CO2?

 

Yeah, with Sti uppipe, your EGT probe is gone or at least it should be. You did do the 2.2 kohm resistor mod right?

 

I don't see how he got the cel if he resistered it. Catless = pissed off service manager where I live.

 

He didn't- the problem was his EGT probe burning up and malfunctioning.

 

Who sells the 2.2 kohm resistor mod or where can i get it done? Id ask how to do it myself but i dont mess with wiring stuff. Awns, i think you're right but i was just relaying what my prof said, doesnt matter anyway since i dont have a cat.

 

You go to RadioShack, you buy a 2.2k Ohm @ 0.5W resistor. You look at the harness where the EGT probe used to go and you shove an end of the resistor into each hole in the harness. Then you put tape over it.

Looking, shoving, taping. Note the lack of cutting, splicing, wiring, soldering or other activities that take thinking. Rocket science, it ain't.

jason