View Full Version : Gen1 3SGE Headers/Downpipe on an ST162 3SFE

12-30-2011, 07:46 AM
Preparing for my 3SGE swap from my GTS into my GT I've been upgrading the suspension, exhaust, etc for the fit. As it stands, the swap won't happen for a few months but I need some exhaust work done soon so I thought I'd start on this. I know that the 3SGE header will bolt onto the 3SFE no problem but I do have concerns about a few things.

1) As far as the downpipe is concerned, I know the lengths are a bit different. If I have the exhaust shop do the proper modifications to accommodate the differences, will I have any issues from the 3SGE swap? Are the exhaust locations relatively in the same location?

2) These are both USDM engines. The 3SFE has a cat on the downpipe and exhaust whereas the 3SGE does not but rather further along the exhaust. How will this affect the engine performance? And smog? Assuming the 3SGE passes smog as it is, in theory this should have no impact right?

3) There are two o2 sensors on the 3SFE header vs the 1 o2 sensor on the 3SGE header. Will that be a problem?

Any insight would be great guys! Thanks.

12-30-2011, 07:50 AM
Answer one question for me first(I'm in tapatalk and can't see location right now), is this a California vehicle?

12-30-2011, 07:53 AM
Yes but not for long. Moving to Washington state in a week.

12-30-2011, 08:02 AM
Okay, the federal 3S-FE has only one one O2. That's what I was wondering. You'll have a different ECU that's expecting the signal from that sensor, so you'll throw a CEL without it. I can't say if it will perform differently, not familiar enough with the California version.

As for the fit, I'm running a header with an in-line cat on my coupe. They'll have to cut the pipe and extend it(or install an in-line cat in the space), but it will work with modification. An exhaust shop should be able to do it without much trouble.

12-30-2011, 08:18 AM
Ah alright. I wonder if I could swap the ECU from a wrecked celica in without any issues to stop the code. That would just bug me plus I think WA state requires there be no CEL codes to pass smog. The car doesn't pass smog as it stands now (just a 60 nox or so above the state limit, sadly).


I'll probably end up waiting until I get to WA to do the exhaust swap but I need a new catalytic converter (in the exhaust section, the OEM cat below the header is a fortune to replace) to pass smog to finish the title transfer before I move up to WA. California requires it to transfer and I don't think I can finish the title transfer up in WA without it.

12-30-2011, 09:50 PM
Dont worry about the O2 stuff. When you swap to the 3sge, you will swap the ECU to a 3sge ecu as well, which will only use 1 O2 senser anyways.

12-31-2011, 08:10 AM
But for reference, the second o2 does not adjust how the vehicle runs, if I recall correctly. It only tells you if the pre cat is not filtering, or filtering too much.

12-31-2011, 03:41 PM
You can just link the wires to read off the same o2, you will run a little rich but who cares.

Sent from my HTC Sensation Z710e using Tapatalk

01-05-2012, 11:00 AM
I found the GE exhaust made the motor lean out - good for emissions
The JDM FE/GE use the same O2 sensor plug
The second sensor you mention is a cat warning sensor on your dash, JDM GE's have it too but all unplugged
There are two different versions of the Gen1 GE downpipes, one has one pipe, the other has two
Problem with the GE header is cracking, check for cracks

Don't just swap the header - the FE exhaust on mine was way narrower than the GE


More reading - http://st162.net/forums/viewtopic.php?f=33&t=7265

01-05-2012, 05:04 PM
For emissions, check engine light normally only matters if the car is 96 or newer. Here, you can have a 90 Celica with a check engine light and they wont car cause the have nothing to connect to the system and check. 95 and older all get the sniffer.

01-11-2012, 06:41 AM
But for reference, the second o2 does not adjust how the vehicle runs, if I recall correctly. It only tells you if the pre cat is not filtering, or filtering too much.

Correct! front o2 adjust fuel, rear o2 monitors cat efficiency.