Jb4 Fmic cp bov dci downpipes all new vacuum lines

Jb4, Fmic, cp/bov, dci, downpipes, all new vacuum lines.

MISFIRE happened right after the downpipe install and they were correctly / professionally installed.

Car is misfiring and has rough idle still,

had two different shops check it out.. they tested all sensors, coils, plugs, injectors, checked for vacuum leaks, even changed the valve cover and pcv valve/ hose, and they all were working like they should but the car is running rich/lean still and the spark plugs in cylinders 1-3 are turning black.

They completely removed the JB4 and the car was still misfiring but sounded like it was running better, with the JB4 on it would sound worse and run fine for a minute or two but then the SES comes on and it runs like shit.

The last shop doesn't feel comfortable working on it anymore because they think it's a DME issue or just needs a proper dyno & tune, any suggestions ?? What do you guys think?

Btw the shops I took it too were certified to work on Mercedes, BMW, Audi, VW, etc

%d comments
  • no they aren't apparently because I bought oem plugs and coils when misfirings started happening after dp install and someone suggested colder plugs and it worked so.....

  • Cars
  • If you understood the reason we run ngk you would have never even posted that

  • You had bad plugs. Period.

  • And lol. Running dp will never required colder plugs.

  • For 7 years people ran fbo and upgraded turbos without ngk plugs. Why werent they misfiring

  • I don't agree with you sorry I went through 12 different oem plugs until ngk fixed it . haven't had a problem since. same thing happened to another member on here after dps and ngk fixed his issue as well.

  • You had bad plugs. Your car isnt modded at all. Its stock. You dont need ngk. Period.

  • These are facts. Its not a debate

  • Lol Matt CR he went thru 12 oem plugs. As if brand new plugs cant be bad right out the box.

  • (I tagged Matt because we literally had that exact issue)

  • Lmaoooooo

  • What a bitch that was

  • Cars
  • Lmao wtf