i have a 91 z28 vert(305 auto) and it seems like lost quit a bit of horses since i got it and i tune it up when its time and i was wondering how i check the egr and how do i change it and how hard is it to change,because it looks like its siitng under the tpi and above the intake. my check engine light comes on sometimes down the road. it might be an hour before it pops on and then it might only take 5 minutes or it might not come on at all.but its usually after i was doing 70 or so and then go to slow down

 

the only good way to test it is by pushing up on the diaphram of the EGR valve...which u cannot do b/c u can barely touch the damn thing. i would just take off the upper plenum and then pull the EGR valve off and see if it clogged w/ carbon and such. clean it out (or buy a new 1 if u want) and stick it back on there and see how it does then.

also,u can check the codes in the computer and see what code it is. bend a paper clip and put it in the top right 2 terminals or the ALDL connector under the right hand side of the dash...above ur right leg when driving and see what code it spits out. remember,it will flash X XX X XX X XX (code 12,means its going into diagnostic mode) and then it will spit the code out and repeat it 3 times. good luck!

 

ok how do i do that and how hard is it do i need new gaskets or what and if i remeber right the last time i did my tuneup i checked the engine light and it came up the o2 sensor and the egr so i changed the o2 but i didnt mess with the egr

 

please help

 

Check or change your EGR solenoid first. That could very easily be your problem. It is a lot easier to get to and cheaper too.