I have an EVO X MR.

When I am moving, say 5th gear at 2/5ths throttle, and goto WOT the engine does a big cough / shutter as it down shifts to 4th. Maybe even a back fire. At this point I have just backed off the throttle for fear of damaging something.

It will do this in any gear really. Not just 5th. Does it in 3rd, 4th and 6th too.

Was using a Cobb Tune but have since went back to stock.

Also, with the Cobb Tune the idle was really inconsistent to the point of cutting off at stop lights on rare occasion. Recently started doing this also.

With the stock tune the idle is back to normal. The shudder thing still persists.


Car has a 3" torbo back exhaust and a Cobb air filter.
Car didn't do this before. Was working fine with the upgrades and Tune.
Could the recent weather change 80^ to 40s have anything to do with it?

Any ideas of what this could be?

Thanks!

Gullie

 

Very possibly. We'd be happy to look the car over for you if it comes to that.

 

The idle with COBB and weather yes. The lean out at tip in you got to look at.