05 WRX STI Woes

[SiriusBlack]

Hey all. Last week I bought a 2005 WRX STI with 67000 miles. Now I am discovering several things that didn't get discovered during the test drive and the owner didn't mention.

It has a Cobb tuning access port that was running a "custom" tune. That tune supposedly added 30 HP, but it killed any and all fuel mileage and was causing a bank 1 too rich code. I reflashed it to the Cobb factory economy tune, now I have 7 different check engine codes. Evap system error/PCV system error and the rest are low sensor voltage errors. It would not let me do the realtime map swaps while it was flashed to the custom tune. Now that it is flashed to a Cobb tuner factory map I can realtime any map other than the custom map.

It has a Cobb short cold intake, a Mishimoto radiator, Grimspeed turbo solenoid controller, and Ohlin race coilovers.

It also has a clicking noise from the tranny. It is worst in second gear, but can also be heard in first, neutral and reverse. It is absent when the clutch is disengaged and you sit still, but you can hear it faintly when rolling to a stop with the clutch in. I discovered much to my anger and disappointment that the tranny had been being run with almost no oil in it for several hundred miles after they had a shop install a new clutch.

Currently my biggest worry is to get the ECU squared away. I want it to run on something other than their custom tune without throwing half a dozen engine codes.

All of my subi experience has been from restoring my BRAT and XT, only 80s subis. This is a bit new for me.

Thanks in advance.

Edited November 5, 2021 by SiriusBlack

[el_freddo]

G’day SiriusB, 

I can’t help with the ECU tune but @GeneralDisorder will be able to help out there. 

That gearbox click immediately had me thinking of a chipped tooth on the second gear’s gear set. It’ll eventually let go completely if not rebuilt. A replacement gearbox would be easier though. You could drain the gearbox oil and see what else comes out and if there are any teeth bits sitting around the drain hole. 

It sucks that you’re in this situation, I bet you paid the Covid tax on this WRX too. They’ve all gone UP in price over here since covid hit, not just WRX’s either - just about all vehicles! 

Cheers 

Bennie 

[SiriusBlack]

Hey all. I recently took COBB's tuning classes, for all the good it did me. Turns out the custom tune the car came with is locked, and my accesstuner software won't read it. In addition the classes they had me take through EFI University, barely touched 75% of the stuff in the software. I don't know what I'm doing when it comes to digital ECU tuning, and I don't want to mess with anything for fear of ruining my motor. I asked COBB if there were any other classes I could take to get a better grasp, they just said to look at their help center. Another waste of time, it barely covers the old STIs anymore. Is there anyone that can help me tune this car? I would be immensely thankful.

[GeneralDisorder]

Engine replacement is minimum $10,000

Find a competent COBB Pro-Tuner in your area and get it properly dyno tuned. This is absolutely NOT something you should be doing on your own or you WILL be buying a new engine AND paying someone to tune it so it doesn't happen again.

Subaru's have ridiculous timing curves that don't match what most other engines run. They have the short block design of an F1 race engine, and the heads and manifold of a tractor. 

Just don't is my suggestion. I own a Subaru performance shop and I employ a full time Subaru tuner (who has the 3rd COBB pro license ever issued back in 2003). 

GD

Edited February 21, 2022 by GeneralDisorder