so were having troubles with my friends accord. It runs fine until you get it past 4 grand and then it throws codes for vtec system malfunction, egr valve lift insufficiency, and idle air control. the revs wont let you get past 4000rpm and seems to be like a rev limiter at 4k. also it bounces up and down at idol from like 500rpm to 2.5k or something like that. thought it might be the idle air control valve so we replaced that and its still bad. any ideas???

 

what codes does it throw?

which one pops up first?

 

the codes are. P1259-vtec system malvunction, P1491 egr valve lift insufficient detected, P0505 idle air control. they come on at the same time.

 

vtec solenoid could be bad