My EVO VIII has been having problems with bucking at over 1/2 throttle in third and forth gear, highway on ramps. The air filter is clean, the NGK Iridium plugs look fine. Always use periam gas. I do mostly city driving and do not get on it very often. What should I start looking at next.

Help

 

Help us help you. Any mods to the car?

 

Any knocking when it is doing this "bucking" did you flash any tune, or update with TehpraMOD to get the CEL knock flash warning? Do a log of the event to be safe. Any wideband to see the AFRs when it is doing this? Mods list would also be helpful

 

tighten up the bov spring if you have one

 

DV on backwards?

Intake snorkel (if on the stock box) Fasteners missing? So at speed it lifts the snorkel and cuts airflow to the turbo

 

Sorry! here is more information. The car is stock.

 

+1 on the intake snorkel. I would look there first.

 

Do a boost leak test.

 

A stock 2003 EVO 8.... unlikely, are you the original owner? If not you are going to need a little snooping to figure out what the previous owner did. Is this a new issue - if so did you change anything recently?

 

Thanks for the help but nothing yet. The intake was not the problem. I am the only owner. I have had the problem for 6 months or so and have had no time to look into it, just kept my foot out of it. Now I would like it gone. Have not done the boots leak yet. Any other ideas? I do not want to take it to the dealer and have no tuner I know near by.

Thanks