duckmaster

I'm having an EGR issue!!!! Truck is throwin a 71 code. I've checked the EGR valve and it seems to be workin properly. I went ahead and replaced all the old rubber sections of the vacuum lines and checked the rigid sections for leaks so when I put the vacuum gauge on the throttle body I get no vacuum. So now I'm at a loss, any ideas about what my problem might be??

duckmaster

actually let me back up a bit. The other day my check engine light came on but the truck was runnin the way it always had. When I checked the code it was throwin the 71 error, that's the only reason I'm sayin I have an EGR issue. I guess it could be something else, would appreciate in insight anyone might have to my problem.

scope103

Did you go through the steps in the FSM? http://personal.utulsa.edu/~nathan-b...77exhaustg.pdf That's where I would start.

One thing to think of with our older trucks is "crud." The PCV system dumps oily stuff into the plenum, right onto the egr pipe. This one has only 30k miles; yours has probably never been cleaned and it could have enough stuff to block the tube entirely. What code 71 is triggered by is an insufficient rise in temperature in that pipe; if it's blocked, that could be a cause.

duckmaster

thanks for the info, I'll definitely check that out this evening!!!

duckmaster

is this EGR pipe what the EGR valve is mounted to???? If not, where is it located and could and if it's plugged up would that stop the engine from making any vacuum pressure??

scope103

The photo shows the pipe laying right above where it goes. You can't miss it.

That pipe has nothing to do with vacuum. The ports on the throttle body only pass vacuum at certain throttle openings; the manual page cited gives you the details.