Invidia vs OEM catted turbo end:
Invidia has smooth transitions inside the pipe, it does also have not an ideal taper on header end.
Compare that to the OEM uppipe, it's like it was purposefully designed to suck and reduce power.
Turbo end shows the cat and EGT, notice how poor the transitions are.
Invidia uppie has a bung for the OEM EGT, but oem EGT is meant for checking the health of the cat only, it's too far away to give accurate EGT, plus it can break and kill your turbo and finally I'm hearing they burn up faster without the cat. You will need a hard to find M12x1.25 bolt, parts stores do sell drain plugs in that size for around $5. I was able to find a plain bolt at local hardware store and cut it to fit.
Gaskets, now is the time to replace those 10 year old gaskets...
Getting the uppipe was not hard, but trying to hold it and bolt a bolt up did get tricky, not enough hand room.
I personally tightened the the turbo bolts before getting the header attached, if you keep them loose it might make it slightly easier to get the header installed.
Get new gaskets on the header, and bolt everything up.
Now I didn't realize this until I started looking for exhaust leaks do to a whiny O2 sensor code. Apparently I put the second gasket ontop of the stock one, fitment is perfect and I see no leaks, thus I think this up pipe might actually be a little short, if it prevents cracks I'm all up for it too!
All of this took about 4 hours, rusty parts and stuck bolts is the main reason for why it took so long. I'll do some Virtual Dyno runs in the next few days and will see how it did powerwise, also will see if MPG improves.
Finally did a virtual dyno, I rest the ECU for both runs, and drove the car until IAM hit 1.0 that way timing would be identical for both runs. Waited for another warm day in November and did another run, compensating for temperature, pressure and fuel/toolbox weight. 7whp/10wtq peak gains!
Do notice the AFR dip, this is a stock sensor thus it only reads to 11.1 and even then it's not accurate. I'll have my MTX-L hooked up after I get rid of the P11. Also please note that this is not necessarily the best road for peak WHP (slight up hill), but it's very easy for me to do repeat runs on this specific road. On a straighter road the car is making 213whp.
Removing the EGT sensor will cause a CEL, thus you have to either reflash the ecu with codes off (best method), or use a resistor patch (will work, but I've had some issues after some time).
Disabling the CEL's through reflash
Disabled these codes in your tune:
P0420 - Catalyst System Efficiency Below Threshold
P0545 - Exhaust Gas Temperature Sensor Circuit Low
P0546 - Exhaust Gas Temperature Sensor Circuit High
P1301 - Misfire Detected (High Temperature Exhaust Gas)
P1312 - Exhaust Gas Temperature Sensor Malfunction
P1544 - Exhaust Gas Temperature Too High
I highly suggest using the reflash route, resistor patch for me would throw intermittent CEL's and cause cruise control to fail. Since I have re flashed the ECU with resistor disabling CEL's, I've never had this issue happen to me.
Get a 2.2-kohm 1/2-watt Resistor (Radioshack # 2711121), this resistor makes the ECU think the EGT is always at 1292 *F.
Tape it off so it doesn't fall out