[Shifterkart26]

Greetings all,
Trying to help a friend. After doing a number of upgrades he started getting the dreaded "check engine" light. These are the modifications.

2010 BMW 335i with a N54 engine with 26,000 miles.

1) Front mounted intercooler;
2) Second stage colder spark plugs and corresponding coils;
3) Aluminum charge pipe (replaced plastic, not performance enhancing);
4) VRSF high-flow catted downpipes; and
5) Oxygen sensor spacer.

A MHD flash was used on it. It had a JB4 chip tune that was taken off.

These are the codes.

- DME active codes -
29F4 - DME: Catalytic-converter conversion.
29F5 - DME: Catalytic-converter conversion 2.
2A15 - DME: Fuel tank ventilation system and purge air system, minor leak.
2DED - DME: Power management, closed-circuit current violation.

Once the codes are cleared, the light will pop on after a short (1 or 2) hour drive.

Has anyone experienced this before? Thank you in advance!

[whyzee125]

He should remove the spacer and check the aftermarket DPs option in MHD. That will keep cat codes away and is a better way to do this--high flow DPS are not efficient enough to keep the engine light off, which is seems like he knows.

It seems like the only other issue may be an evap leak. Could be a gap cap, purge valve, or a few other things. I'd start there, clear the codes and see what returns.

[Shifterkart26]

Originally Posted by whyzee125

He should remove the spacer and check the aftermarket DPs option in MHD. That will keep cat codes away and is a better way to do this--high flow DPS are not efficient enough to keep the engine light off, which is seems like he knows.

It seems like the only other issue may be an evap leak. Could be a gap cap, purge valve, or a few other things. I'd start there, clear the codes and see what returns.

Thank you Whyzee125, this is great info.

[lookalikehuuh]

Everything Whyzee125 said,

You didn't mention this, but I assume he is running stock turbos on something like stage 2+ or similar?

If so he really shouldn't be running the 2 stage colder NGK plus, he should be using OEM Bosch plugs. The colder plugs are really for those that are pushing big boost with upgraded twins or single turbo conversions.

Does your friend have any aftermarket stuff on the car like a Chinese headunit or amp? That 2DED code is a generic code that apparently is common when you have higher than expected power drain. Or did you leave something plugged into the OBDII port?