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Demod?

739 Views 9 Replies 4 Participants Last post by  JaySin
Hello all, just joined the ranks of WRX owners! I picked up a 2015 WRX from a dealer that already had a few mods installed, but in order to insure the warranty stays intact, the car ECM was replaced with a new factory ECM by the dealer.

I can't be sure, but it appears the car has the Cobb Big SF CIA and perhaps the Cobb catback exhausted. Everything was working fine, but now I'm getting a CEL. The dealer ran the code and it is due to a lean fuel condition. They believe resetting the exhaust back to stock will stop the car from throwing the CEL, but from everything I'm reading, the lean condition is most likely from the CIA.

Would I be right in requesting the dealer reinstall a stock air intake so the lean condition will go away?

Thanks!
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Stock airbox unless you have an AP and can flash to the correct map
Hello all, just joined the ranks of WRX owners! I picked up a 2015 WRX from a dealer that already had a few mods installed, but in order to insure the warranty stays intact, the car ECM was replaced with a new factory ECM by the dealer.

I can't be sure, but it appears the car has the Cobb Big SF CIA and perhaps the Cobb catback exhausted. Everything was working fine, but now I'm getting a CEL. The dealer ran the code and it is due to a lean fuel condition. They believe resetting the exhaust back to stock will stop the car from throwing the CEL, but from everything I'm reading, the lean condition is most likely from the CIA.

Would I be right in requesting the dealer reinstall a stock air intake so the lean condition will go away?

Thanks!
Wow that dealer has to be playing dumb trying to pin a CEL on a catback exhaust. You're getting a CEL because the WRX you bought was most likely traded in at that dealer with Cobb Stage 1 Tune Package and when the dealer replaced its ECM with a stock ECM the car was no longer running on the map for that intake. So you cobb intake is making you run lean on a stock tune. If the dealer is trying to solve the issue then 100% ask for a stock air intake to replace any stage 1 parts.

Maybe avoid driving it if you can since its running lean.
Hello all, just joined the ranks of WRX owners! I picked up a 2015 WRX from a dealer that already had a few mods installed, but in order to insure the warranty stays intact, the car ECM was replaced with a new factory ECM by the dealer.

I can't be sure, but it appears the car has the Cobb Big SF CIA and perhaps the Cobb catback exhausted. Everything was working fine, but now I'm getting a CEL. The dealer ran the code and it is due to a lean fuel condition. They believe resetting the exhaust back to stock will stop the car from throwing the CEL, but from everything I'm reading, the lean condition is most likely from the CIA.

Would I be right in requesting the dealer reinstall a stock air intake so the lean condition will go away?

Thanks!
Wow that dealer has to be playing dumb trying to pin a CEL on a catback exhaust. You're getting a CEL because the WRX you bought was most likely traded in at that dealer with Cobb Stage 1 Tune Package and when the dealer replaced its ECM with a stock ECM the car was no longer running on the map for that intake. So you cobb intake is making you run lean on a stock tune. If the dealer is trying to solve the issue then 100% ask for a stock air intake to replace any stage 1 parts.

Maybe avoid driving it if you can since its running lean.
Thanks. Based on all the research I have been doing on the issue, this is the conclusion I had come to as well. I told the dealer this, but his "master" service tech said there should be no issue with the Cobb CIA. He thinks the issue is the O2 sensor in the exhaust. I even pointed out the warning on Cobb's site that states the car will require a map with this intake installed.

Thankfully, getting this car running correctly is being done at their cost. I only bought the car after getting a signed agreement from the used car manager stating they will make sure it is running correctly. I can't understand why placing the stock intake is such a problem for them. At least I can call them on Tues and point them to the resources I've found.
The dealer needs to put the stock intake back on...period. Then go from there. Insist on it.


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Thanks guys! I spoke with a Cobb authorized installer today and he agreed with all of your assessments. I spoke with the dealer and he has agreed to have his tech call the Cobb authorized installer for confirmation. Hopefully this will get everything working properly so I can to really begin enjoying my car.
So, status update on the car. It turns out the car had a turbo back exhaust on it as well. The dealer has replaced the exhaust with a stock exhaust and is waiting on the stock air intake to finish the repair. Thankfully, this is all being paid for by the used car department. I hope to pick the car up early next week.

I'll probably look to put mods back on the car after the factory warranty expires, but that's at least 2 years away.
Ok, I think we have finally finished working through the issues with the car and it has been returned to proper operating condition.

Here's a list of all the things the dealer ended up having to do to reset the car. Thankfully, this was all on their dime as they made a promise to get the car back under the Subaru warranty.

1. Replace ECU with factory ECU (the Cobb Tune was still on the ECU and they couldn't do anything with it)
2. Remove Cobb TurboBack Exhaust system and replace with stock exhaust system
3. Replace faulty rear O2 sensor
4. Replace faulty Air Flow sensor
5. Remove COBB Big SF Air Intake and replace with stock airbox

My car is running good and thus far, no lean codes have been thrown again. Now, I'll be back in this section again in a few years to see which engine mods I might consider at that time. I'm already thinking about looking at an axleback exhaust at some point. I do miss the rumble of the COBB Turboback.

I really appreciate the advice you guys gave me through this! Thankfully, the dealer finally listened!
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