Ok, so I just finished mounting my RB true duals and started it up to check for leaks and sound (sounds awesome btw). I haven't started the car in months and now I get a check engine light. What could be causing this?

Projects completed or underway so far:
Road Race Exhaust - s5 - split air pipe removal (just plugged with a bolt) - Complete
RB Sways - complete
New Shox/struts - need to finish mounting springs and then install
Replaced U-Joints - Complete
New Battery - Complete
o2 sensor - Still have the old on on the headers, I assume it works but i bought a new one to be safe (Bosch universal)

Is it possible that the old o2 sensor gets too hot in the headers, or that my fingers may have touched the element when installing? I have a new one to replace tomorrow. I will update then but I'll take any other ideas too.

 

i had this happen to me when i plugged the split air pipe. that could be the cause, or the o2 sensor of your could be it too.

 

I would guess that your aux ports no longer function & that the stock air pump system is not functioning as well... they are part of the same thing. I'm not sure what to do about S5... I ended up removing the stock air system & solenoids & re-making my own air system. I'm happy with it but it's a long way to go to get where I needed to be. keep in mind I had an S4 with an S5 intake on it & needed to activate my 5th & 6th ports as well as the VDI. Possibly you need to block off the split air pipe so that your system remains pressurized enough to activate your aux. ports.

Ramses666

 

the air pump opens the 5th and 6th ports on s5 modles. he should be fine. also he already has the split air pipe blocked off and that won't cause the system to remain pressurized to open the ports.

 

your probably right... must be something else.. get a code checker to figure out what is wrong.

Ramses666

 

Where can I get a code checker?

 

to my knowledge nobody makes a code reader for these cars. blink codes is the way.

 

Check your o2 connector and wiring.

 

Where did you block off your split air pipe? From the host on the LIM? I just left mine open when i removed the pipe. It wouldn't cause a CEL though.

 

YOu probably removed the ACV or didn't reconnect the two solenoids on it. That will result in a code. Lack of 02 sensor gives a code.

A code checker is in existance. See Mazdatrix. But that seems wasteful.

 

What's the acv? I reconnected the wiring for the o2 sensor, clicked it back into the harness.

 

Looks like a new o2 sensor did it. No more check engine light. FYI, a Bosch Universal fits perfectly for $17.99 from AutoZone. The oem is $150 and I said hell no to that. The guy @ autozone said I should be ready for a real pain in the *** with a Universal. This leads me to believe that others may think this too about the Bosch. I put on the new universal on my RB Headers in less than 5 minutes. Works great.

 

Scratch that, now it's back, but only when I'm off the gas now, on idle/decel. I'll do a search for this but if you know anything, feel free to jump in.