Error codes P2096, p2087, P0139 after engine mods

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cafri3
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Joined: Mon Apr 28, 2008 11:52 am

Error codes P2096, p2087, P0139 after engine mods

Post by cafri3 »

I have a 2006 MX-5 "sport" model, about 40,000 miles. It has a 6 speed manual trans, and have done the following engine mods over the years: Cobalt cold air intake, K&N air filter ( in2007), engine oil cooler (2008), short throw shifter (2008), OBX header(2009), and Magnaflow cat back exhaust (2011). After I installed the header, the two O2 sensors went right into the same location as "stock", the code P0139 came up, (Rear h2os circuit problem). I then installed a 02 sensor device that moved the sensor back a bit from the regular gas flow; the code still appears.

I then installed the magnaflow cat back exhaut, and within 40 miles additional codes P2096 and P2097 were "thrown".
The combination of all the mods has made the engine scream. Each mod was done with months/years between, and I could notice by "seat of the pants" driving the car rev'd better and higher with each additional mod seemed like more power, and occasionally get a chirp out of 3rd and 4th gears on spped shifts. Below are the codes from my scantron code tool.

P2096 Post catalyst Fuel trim too lean, Bank 1
P2097 Post catalyst fuel trim too rich, bank 1
P0139 o2 sensor circuit slow, response 1/2

Are there any recommendations to clear the codes, perhaps upgrading/reprogramming the ECU? Perhaps relocating the O2 sensor to behind the catalytic? When I clear the codes with the scantron, they come back within 50 miles.

If an ECU, any suggestions for make?

Thank you for your reply.

2006 MX5 sport, black, in Maryland.
2006 MX-5 Sport, 6 speed manual, black on black
Brian
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Re: Error codes P2096, p2087, P0139 after engine mods

Post by Brian »

Stock setup includes converter in the header and ECU expects to measure the difference before and after that converter. By pulling factory header with converter and just putting the sensors in the same location that guaranteed engine codes. It sounds like you still have factory converter in the midpipe. Assuming so, you can move second sensor so that it measures AFTER that converter and it should help your code issue. Note we do have extension cord on the website to make this process easier.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
cafri3
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Joined: Mon Apr 28, 2008 11:52 am

Re: Error codes P2096, p2087, P0139 after engine mods

Post by cafri3 »

Would the moving the o2 sensor behind the cat, with the extension cord possible resolve the issues of the P2096 and P2097 codes as well? Would the delta force commando miata tuning kit help with the rich/lean situation? The Magnaflow exhaust made the engine run great at high rpms, but seems to drone when below 2500 rpm. Also, engine seems to have less torgue at lower rpm(<2500) Prior to exhaust cat back, it ran very well from 2000 rpm up, now 2000 seems to low...??? I never drive below 2000 rpm, and cruise between 2000 and 3000 rmp, uxcept when tromping the gas pedal for the fun factor

I'm trying to find that happy balance between performance and gas mileage; will running at higher rpms affect MPG much?

Thank you.
2006 MX-5 Sport, 6 speed manual, black on black
Brian
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Re: Error codes P2096, p2087, P0139 after engine mods

Post by Brian »

This motor was not designed for efficiency at low rpms...and driving around at 2000 rpms is way below what was intended. In fact the header and muffler and intake are doing nothing for your power or efficiency at such low rpms. If you want to lug the motor around so low then you would be much better off, and solve all your issues.....if you put all the stock stuff back in. Seriously...you are wasting your time for a motor that is being lugged around....likely with less efficiecy than stock.

Tha OBX header has been a source of nonstop issues for owners which is why you dont see it sold at any mainstream parts vendors. I suspect you could tune around the problems but you know what they say about putting lipstick on a pig... I suggest just going back to stock header because you are getting nothing but problems from that OBX header.....and doing so will help that drone issue. Last OBX head i saw had one primary nearly blocked...and another more open than the remaining two with result that the car managed to run both too lean (in one cylinder) and too rich (in another cylinder). Sounds familiar right?
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
cafri3
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Joined: Mon Apr 28, 2008 11:52 am

Re: Error codes P2096, p2087, P0139 after engine mods

Post by cafri3 »

Thanks for the comments Brian. It brings up the old addage "you get what you pay for", I saved a couple hundred on the OBX header, but install was seriously painful (nuisance) and not "drop in" as advertised.

I'd hate to even think about changing back to stock header, easier to drive at higher RPMs and relocate the 2nd O2 sensor to behind the cat. Alternately, would a different header help?

Would the commando tuning kit assist with extra power, especially at redline? ONce I hit 7000 rpm, the rev limiter kicks in, but engine seems to have lots of rpm left as it pulls strong up to redline, then seems to shut off (either starving for fuel or rev limiter kicks in)?

Caroll
2006 MX-5 Sport, 6 speed manual, black on black
Brian
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Re: Error codes P2096, p2087, P0139 after engine mods

Post by Brian »

Yes, more power is up higher.....particularly when a good highflow header and exhaust is included. Yes, for 06-08 application our Moto-East can include a higher redline.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
cafri3
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Joined: Mon Apr 28, 2008 11:52 am

Re: Error codes P2096, p2087, P0139 after engine mods

Post by cafri3 »

A quick update to the error codes from installing a header last spring: Per Brians recommendation, I purchased the extension cable and O2 bung kit to relocate the 2nd O2 sensor behind the remaining catalytic converter in the mid pipe about two months ago. After initially doing this, I cleared the codes, and since then I haven't had any engine codes come back. The engine seems to run better, and the "pop" heard when shifting went away as well. I believe the engine was trying to toggle between rich and lean, and couldn't figure out a happy compromise. Now with this change my gas mileage jumped from a degraded 23 mpg back to 25 to 28 mpg (depending on city/highway), and I have hit 32 mpg on spirited highway driving. Thanks for the advice Brian.

My advice to anyone considering headers for MX5, don;t get the OBX header, although less expensive, they were extremely difficult to install, required grinding of the motor mount and the body panel to clear. Spend the extra $$$ for the headers which Goodwin sells.
2006 MX-5 Sport, 6 speed manual, black on black
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