O2 Sensor?
 

Hey all, yesterday I was making a road trip to school in West Virginia. On the way, my check engine light went on. The only work I have done is a cold air intake, aftermarket catback exhaust, and aftermarket test pipe with a secondary cat delete. I would imagine that the check engine light is on due to the O2 sensor picking up that my secondary cat isn't there. With that being said is there anywhere around Morgantown, WV that I can get my car tuned? I don't have the knowledge to do that stuff and would prefer to do it here rather than making another trip home. If you have any other suggestions let me know. Thanks.

No, the ecu only monitors the cat in header, the secondary cat is not monitored.


see Basic Bolt on Mods Guide link below.


The CEL light is likely due to the aftermarket CAI throwing of the MAF sensor scaling or if it has oiled filter, oil on MAF sensor.


This will result in codes such as Air Fuel imbalance or rich/lean codes due to fuel trims maxing out.


Or you have intake air leak or installed intake incorrectly


But you really need to get a odb scanner and read the CEL code from ECU to be sure.

Start here first. You can get one from any auto part store for about $80. It's a great investment.

Yep and yep ^ ^

If the code reader indicates that the MAF is all gummed up, you can buy MAF cleaner at the same auto parts store as where you purchased the code reader.

Bubba says they also sell electrical tape, that you can use to tape over the check engine light .....:confused0068:


humfrz

I don't like Bubba.

Thanks for all the responses. I was planning on getting an OBDII scanner anyway to diagnose the problem before I walked into somewhere without knowing the actual problem lol. I'll post again once I have the code.
@steve99 could you elaborate on that oil part? My last oil change was ~2500 miles ago. CAI also makes sense I believe everything was installed correctly but tune was recommended with that as well as the test pipe. But first I'll get the OBD scanner and take it from there. Thanks for the replies!

I believe @steve99 was referring to the CAI, if you are using an oiled filter. Sometimes excess oil can get sucked off of it onto the MAF, gumming it up and causing funny readings.


humfrz

Some air filter elements are supposed to be oiled. The oil pulls out of them and contaminates the MAF.

edit: yeah, what humfrz said.

Ya, sometimes I feel Bubba should stick to working on old John Deere tractors......:sigh:

POW-POW


humfrz

I'm a little late to this thread, but just FYI:

1. You can walk into any O'Reilly's, Advance Auto, Auto Zone, etc. and ask them to pull the codes for you. They all keep an OBDII reader behind the counter and will walk out to your car to read the codes for free. Then they'll look the number up on their computer and give you the description. It's usually a good idea to write it down. They're easy to forget, and many codes sound alike, so it's also easy to "remember" the wrong one. It's really a free service. There are no catches. They're just hoping it causes you to buy parts from them.

2. You can use Torque (Android) or DashCommand (Iphone) to read, research and clear OBDII codes from your car on your phone. Torque has a free version that will read codes, whereas the full version that clears codes and has real-time monitoring is $6. Then you need a $20 (or less) OBDII bluetooth adapter you can get from Amazon or Ebay. DashCommand uses a wifi adapter, and it used to be a little more expensive, but I haven't checked the price lately. You get more features on these apps than on a $300 pro model code reader, and the graphical interface is a lot friendlier. All for under $30.

I run Torque full time in my BRZ on an old phone I have dedicated to that purpose. I usually also carry another OBDII adapter in my Jeep to read codes off my regular phone, but the last time I threw a CEL I was 600 miles from home and had forgotten to put the adapter back in the glove box. So I just popped into an O'Reilly's store, had the code read to verify that it wasn't anything serious, and went on my way.

Bump. Sorry to pull up an old thread but my CEL pinged again. The code is P219A "Bank 1 Air/Fuel Ratio Imbalance." As I said before I have a K&N CAI and an Invidia test pipe and catback. Secondary cat is gone. I bought an accessport from OpenFlash since Cobb discontinued its accessport for the BRZ and I tuned it but the CEL pinged yesterday with the same code. I'm not sure what the problem is as the person who tuned it for me said everything looked good. When I'm low in RPMs, especially at low speed, there is a delay/stutter and I can't push the pedal down all the way or I'll just stall. If anyone can help me out it'd be appreciated and I'll provide any additional info you need.

Do a log where this happen.

I assume your K&N CAI threw your MAF-Calibration off. Put the Stock Intake back on and give it a try.

If your getting P219A lean condition then you have a problem with intake or exhaust leak or dirty maf or possibly o2 sensor fault. If you have only changed intake id start their and check for leaks incorrectly installed maf sensor their is a gasket under maf that is easily creased or torn. Clean maf with maf cleaner if you have oiled filter.

The code you would get for cat removed in header would be P0420

So I just got off the phone with someone at K&N. They told me if I've had the CAI for almost two years it's most likely not the intake unless I didn't take care of it. I've only put about 8k miles on that intake at most, so I really don't think that would be an issue; however he said since my secondary cat is bypassed I have to turn the sensor off for that cat. Does this seem right to you guys? Just looking for a couple of opinions. Thanks.

So did you try any of the suggestions given in this very thread?

Bold bit is incorrect,

1. only primary CAT in header is monitored by ECU. Secondary cat is not monitored.
2. The cel code produced when you remove the PRIMARY CAT in header is P0420, not a lean code PP219A "Bank 1 Air/Fuel Ratio Imbalance.
3. Removing even both cats will NOT cause the lean code just the code P0420 cat efficiency. assuming the 02 sensors was not damaged and installed correctly no exhaust leaks.
4. Even straight piping the entire exhaust wont cause car to run lean.

you have a perceived lean condition could be many things. see my previous posts and like another guy said you need to monitor LTFT , commanded AFR and Actual AFR.