I have a 2005 Evo8 with 250,000 miles. Last 4 years I have had brief intermittent losses of power while accelerating. In after market stuff I have a new "chip" which leans down the fuel/air mixture, after market intercooler, after market exhaust.I had a engine rebuild in 2014.If anyone knows what to do about this I would appreciate it!

 

I'd start by getting rid of that "chip" and go from there. Then, you can start eliminating other possibilities.

 

O.K. thanks! That will probably be the easiest place to start.

 

No prob, Bob. It's usually best to eliminate added stuff from the equation so you don't chase your tail. If I had a dollar for every time a chip, turbo timer, or after-market alarm caused a problem, I'd be a rich man

 

Boost leak test would be next and changing the sprk plug after that. If you noticed a power loss it probably you compress air leaking from maybe a coupling for me I to replace the o ring the the trottle body. Which are common to leak on the 8 and 9. but do the test first

 

Thanks will share with my mechanic soon. Tim

 

Boost leak would be a continuous loss of power, not intermittent. Plugs are a possibility, but I assumed those have been checked.

OP: also check the turbo for shaft play, as well as signs of the wheels hitting the housings. I had a similar problem as you when my turbo was on its way out.