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**Pat McCrotch** · 07-27-2013, 04:06 PM

Mine came on yesterday. Plugged the SCT in and code says Random misfire detected. anyone had this yet?
31,000 miles on the car, Is it time for a tune up? new plugs etc? I do not know a lot about engines, but can change plugs if thats all i need to do.
What else could it be? any input will be appreciated.

Thanks

**JDMLOL** · 07-27-2013, 04:12 PM

Originally Posted by Pat McCrotch

Mine came on yesterday. Plugged the SCT in and code says Random misfire detected. anyone had this yet?
31,000 miles on the car, Is it time for a tune up? new plugs etc? I do not know a lot about engines, but can change plugs if thats all i need to do.
What else could it be? any input will be appreciated.

Thanks

Could be a lot of different issues. The cheapest would be to swap coils on the misfiring cylinder and see if the misfire moves. If it does move, replace it. I typically replace all of the coils and plugs for good measure. If you can and it's still under warranty, put it to stock and take it in.

**Pat McCrotch** · 07-27-2013, 04:34 PM

with headers and catted X, cant really put it back to stock. and not sure what one is misfiring, it just said random misfire detected. Guess i will change all of them and go from there. Thanks

**JDMLOL** · 07-27-2013, 04:43 PM

Originally Posted by Pat McCrotch

with headers and catted X, cant really put it back to stock. and not sure what one is misfiring, it just said random misfire detected. Guess i will change all of them and go from there. Thanks

I meant the tune. Idk how they'd feel about exhaust but some dealers are more lenient than others.

**Yagermeister** · 07-27-2013, 06:34 PM

Have you recently changed your clutch?

**Pat McCrotch** · 07-27-2013, 07:49 PM

Sometimes, I wish the car had a Clutch...

**Yagermeister** · 07-27-2013, 08:12 PM

Have you changed the converter recently?

re-rx7 · 07-27-2013, 08:19 PM

Weird. I went to downshift mine today from 3rd to 2nd and my car hiccuped and flashed the check engine light just for a sec. Back to normal after that.

**Pat McCrotch** · 07-27-2013, 08:31 PM

Originally Posted by Yagermeister

Have you changed the converter recently?

Nope... Happened 1st a few days ago, I changed the tune that I have been running for over a year "93S" to the 93R. I had been so happy with the 93S I forgot about the 93R, so I tried it, code came in after 10 min of driving. Put the 93S back on, code went away, then 2 days later came back yesterday.
Last night, I loaded a different tune from different company, drove to and from work today with no issues yet, but is still idling a little rough.

**Yagermeister** · 07-27-2013, 08:55 PM

Clear the KAM and do an idle relearn and you'll probably be good

**Pat McCrotch** · 07-28-2013, 08:15 PM

I will try that when I get back in town.. One thing I did notice before I left, It looked like one of the hoses going to the Moroso air/oil separator was collapsed in one spot.
I am definitely going to get better hose to change that out, but could this be what caused the random misfire code?

**Yagermeister** · 07-28-2013, 08:44 PM

Not sure about that but IF you had changed your clutch or converter you should do a misfire profile correction procedure at the dealer.

**Yagermeister** · 07-29-2013, 09:15 PM

Loose crank position sensor maybe?

**ochoblanco** · 07-29-2013, 11:04 PM

Originally Posted by Yagermeister

Loose crank position sensor maybe?

This...common issue on the coyotes. You could also pull a plug to see if its fouled. I know mine were fouled out bad from the Trackey programming running lean up top.

**46Tbird** · 07-30-2013, 09:20 AM

Mine got a steady Check Engine Light two days after the engine was replaced. It came back with random misfire codes for various cylinders. The dealer tech had to do a 'crankshaft position relearn' process and that cured it.

PS - I don't like your 'idling rough' comment because that was the first symptom of my piston letting go. After about five miles of rough idling, the CEL came on steady, then the next morning it began flashing. The piston on cylinder 8 had cracked the top ring land. Hope yours is something else.