service Engine Soon light

1999 3.1 v6 78k today the service engine soon light came on.... still runs fine and I see that, that light means its emision control crap. Does anyone have any things i check my self to see if i can save a costly trip to a repair shop??? ANy ideas are great and where are the ports to add freeon to the a/c?

Thanks Derek

Hello,If there is an Auto Zone parts store near you,They can hook op a scan too for free.At least you can find trouble code.I just bought a 1995 Monte Carlo.I charged my air conditioner today.The low-side fill port is located on the left,(Drivers side),Just below the air filter box. Your check engine light may be on ,Because your refridgerant in your A/C system may be low. Let me know what whats up.Diesel 1962

1999 3.1 v6 78k today the service engine soon light came on.... still runs fine and I see that, that light means its emision control crap. Does anyone have any things i check my self to see if i can save a costly trip to a repair shop??? ANy ideas are great and where are the ports to add freeon to the a/c?

Thanks Derek
It's not always an emissions problem that trips the check engine light, although they do cause most of the CEL faults. I agree w/the post above, although I just did this myself a couple months ago and they didn't hook it up, I had to pay a $200 deposit and hook it up and read the codes myself. But they give the deposit back as soon as you return the scanner. Other than that, no way to point you to the direction of the problem, especially since you aren't able to provide the code it's throwing.

Hello,Diesel here again.The A/C code would be number 66,A/C pressure switch.If it is an EGR issue,It would be codes 75,76,77. When I recharged my A/C system,I removed my EGR valve assembley,And found it to be clogged with carbon deposites.This I found out is a common problem with these engins.I took some carb cleaner and carefully cleaned the EGR valve assembley.Also disconnected the battery for about five minuts.Engine light did not come back on and my A/C blows ice cold.If you take EGR valve off,You might want to replace the base gasket.Let me know what happens.I can be reached at trainmaster1962@ yahoo.com.Good luck!Diesel 1962

:grinyes: Where is the EGR valve located on the Z-34 1995 monte Carlo enginelooking to change mines

:grinyes: Where is the EGR valve located on the Z-34 1995 monte Carlo enginelooking to change mines
The EGR Valve is typically located on the intake somewhere.. either on the side or top.