CEL P0121 and P0221 (OFT tune + EL Catless Header)

[andy86]

Recently swap back to stock exhaust. My BRZ has OFT and EL Catless header. No CEL before swap back to stock exhaust. However, I don't feel any problem or hesitation of acceleration while driving. I am going to delete the error code using OFT and see if the codes comes back.

Do you guys have similar situation before? Many Thanks.


I search CEL codes. It is related to Throttle Position Sensor.
Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem


According to some general error code guideline.
Symptoms of a P0121 trouble code could include:

• Malfunction Indicator Lamp (MIL) illumination (Check Engine Light or Service Engine Soon light)
• Intermittent stumble on acceleration or deceleration
• Blows black smoke on acceleration
• No start

Common Problems That Trigger the P0221 Code

• Defective Throttle/Pedal Position Sensor or Switch
• Dirty or carbon-filled Throttle Bore
• Torn or jammed floor mats
• Faulty or corroded Throttle/Pedal Position Sensor/Switch wiring or connections

[shellslinger]

Hopefully someone can chime in real soon!

[steve99]

https://www.autocodes.com/p0221.html


http://www.autocodes.com/p0121_subaru.html

Both codes relate to the throttle position sensor, check plugs at throttle body.

You somtimes get random codes after a ecu flash. If it occurred directly after flash that likely the case.

extremly unlikely it tune related

when you start car directly after reflash let it idle for at least a minute and dont touch throttle during that period, ecu is calibrating all sorts of things during that period.




Clear the codes if they dont return , happy days, if they do they you likly have a problem with the throttle sensors or wiring connectots or throttle body.

[andy86]

Originally Posted by steve99

https://www.autocodes.com/p0221.html


http://www.autocodes.com/p0121_subaru.html

Both codes relate to the throttle position sensor, check plugs at throttle body.

You somtimes get random codes after a ecu flash. If it occurred directly after flash that likely the case.

extremly unlikely it tune related




Clear the codes if they dont return , happy days, if they do they you likly have a problem with the throttle sensors or wiring connectots or throttle body.

Thanks Steve. I will see if it is coming back. Happy New Year.

Sent from my A0001 using Tapatalk

[steve99]

Originally Posted by andy86

Thanks Steve. I will see if it is coming back. Happy New Year.

Sent from my A0001 using Tapatalk

i think i remember somone with similar codes, he had some crud stuck in the throttle plate stopping it closing\opening fully , bit if air filter or something, think a mouse or rat chewed through air filter getting at seeds stuck in filter. weird stuff happens

check the throttle plate in throttle body if it comes back

[andy86]

Checking throttle body and plate is great idea.

Sent from my A0001 using Tapatalk

[andy86]

Want to update this issue. The CEL P0121 was happened on 12/27/2016. Yesterday, it happened again. So, it is 2 months and about after I deleted the CEL using OFT. In this two months, I drove at least 2500 miles. Currently, the car only have about 6800 miles.


With or without the CEL on, the car still feel strong. I can still accelerate to redline without any issue.


So, I delete the code again and see how long it comes back. I didn't have chance to open up the throttle body since it didn't comes back for so long.


Subaru has 5 years warranty related to engine issue. So, may be I just wait until it show more often and bring it back to fix it. (it is a hassle since my BRZ has after market header and light weight pulley)


Anyway, I will keep you guys post.

[Tcoat]

Originally Posted by andy86

Want to update this issue. The CEL P0121 was happened on 12/27/2016. Yesterday, it happened again. So, it is 2 months and about after I deleted the CEL using OFT. In this two months, I drove at least 2500 miles. Currently, the car only have about 6800 miles.


With or without the CEL on, the car still feel strong. I can still accelerate to redline without any issue.


So, I delete the code again and see how long it comes back. I didn't have chance to open up the throttle body since it didn't comes back for so long.


Subaru has 5 years warranty related to engine issue. So, may be I just wait until it show more often and bring it back to fix it. (it is a hassle since my BRZ has after market header and light weight pulley)


Anyway, I will keep you guys post.

So you have a tune, header and pulley but this is a warranty problem?

[andy86]

I think that Dealer usually blame on your mod when they have engine issue. With OFT and header, I am sure they will void my warranty if I am taking it back to dealer. I guess, if my car have more obvious issues like unstable idle speed, black smog and acceleration problem, I probably will put all engine relate mod back to OEM and bring it to dealer for CEL.

[andy86]

Want to update about the issue. According to Shiv of OFT, it should be related to Throttle Pedal Position Sensor and not related to OFT mod. I made a decision to buy a replacement of the Pedal Position Sensor - part number 36010CA070. Although, my car is still under warranty, I wouldn't want to bring the car back to dealer for many reasons. I found used one on Ebay selling it at around $40.


It cost about $110 new.
http://parts.subaru.com/p/Subaru__BR...6010CA070.html


It was a very easy installation. 2 screws and unplug a connection.


Test drive the car after installation, it seems the car accelerate a bit more smooth. Let's see how it go after few thousand miles.