Tracking down a misfire at various boost levels from 15-25 psi with fairly new Denso IKH24's that are 6 months old on my Evo IX.

Pulled the exhaust CPS just to look at it and a good amount of oil came out and was coated all over the CPS.

Since this is my first evo (20+yr DSM guy), I am assuming this is bad, but wanted to check with you guys.

Is the CPS housing where the CPS is installed supposed to be dry?

Could this cause misfires on boost?

Also, if anyone knows how to log the CPS with Evoscan, please point me in the right direction.

 

my moneys on a coil

 

Very possible, ordered some Honda coils to build a COP system.

Nonetheless, is that CPS housing supposed to be dry or full of oil with oil coating the CPS sensor itself?

 

Yes oil can get in there. There even a drain hole drilled in the bottom

 

wet. my bet is on the sensor. they have a limited life.

 

Do you happen to have the evoscan data to log this?

 

I did at one time, but there is nothing obvious to point to the CPS. It just looks like misfire with a big lean spike in AFR. I initially thought it was a fuel system issue because it would drive fine off boost. As soon as I got into boost, the motor would fall flat on its face about 80% of the time. Never got a CEL.

 

Ok, no biggie, I've been wanting a COP system for awhile, so this is a good excuse to build one. If it doesn't fix the misfire, I'll replace the exhaust CPS.

Thanks for the info!

 

i have a good 8 exhaust cps if you need one and they interchange. which i think they do

 

They do interchange, but why would you want to get rid of it? Hit me on PM if you want to discuss..

 

You can get one from an auto parts store for like $50, why wait until you spend money on a COP to see if it goes away?

 

Because I've already ordered the coils and wanted to do this anyway... Cost is like $100 total, not buying a high end COP setup

Replacing the CPS will be the first thing I do if the COP doesn't resolve it.

 

My money is still on the cam sensor...

 

Hyundai/Kia CPS is also interchangeable if sourced cheaper or easier than Mitsu ones:

39310-38050

Beck/Arnley parts are also good aftermarket alternatives.

 

Update:

New COP system resolved the misfire.