Crossover pipe and spark plugs changed now runs like trash.

[Schwebel]

So today I installed new one step colder plugs and a ram air crossover pipe. I am E30 dizzy flash tuned with MP215 airbox and Mountune intercooler. I checked all the connections from the turbo through the intake and everything is good. Car idles smooth. However once I hit boost it feels like it is missing hard. Checked all my coil connections. But figure if it was plug related it wouldn’t idle well.

When I check all my connections there seems to be a manufacturer defect on the breather hose bung on the crossover. My yellow o ring was shredded. Could this be my issue? Kind of at a loss of where to go next. Mine is a 2017. Anyone know the size of the breather hose? Thought about just buying the whoosh breather hose and seeing if that fixes it. Or tuning to an auto parts store to find a reasonable facsimile.

 

[Jabbit]

Did you gap your plugs?

 

[Schwebel]

I had them pre gapped by whoosh. So found the problem, must have a bad plug in the new ones. I put the old ones in and the car runs fine now. Probably one made at 4:45 on a Friday. I’ll get another set ordered. Also filed the defect on the crossover pipe and happened to have an o-ring that fit, so all is good.

 

[FiestaSTdude]

I would check the gap on your whoosh plugs to see if that’s the issue

 

[dhminer]

I would check the gap on your whoosh plugs to see if that’s the issue

This. “Pre-gapped” means “close to pre-gapped” and should still be verified. Also be sure the ignition coils fully seat. They can be a bit finicky.