Cadillac Repair: 95 STS EGR Problem, fuel pressure regulator, seville sts

Question
I have a 95 Seville STS, the ses light is always on and i have a code P036-EGR valve pintle position out of range. now the car works great but however when accelerating heavy it smokes black would this be caused by EGR valve? and do u think replacement would be the answer?
   I also would like to know about my fog lights and ac? the a/c stoped working i have no messages the compressor does not come on at all and the blower works fine, no codes, could this be a relay? and fog light stoped working also at a later date, park lights will come on so i dont think its the switch, maybe another relay problem? and where are these relays located and how can i test them?    thanks very much for any help u can give, it will be well apprieciated!


Answer
Hi Terry, I have replaced alot of EGR valves for that code however it might not cure the black smoke which is a sign of too much fuel going into the engine. Some things to look at are tps adjustment, oxygen sensor changing voltages, a fuel injector leaking or a faulty fuel pressure regulator that allows gas to go into the vacuum hose....As for the fog lights and a/c operation it very well could be a relay. Testing them would require a wireing diagram and voltmeter or 12 volt testlight. In your case it might be easier to just swap a relay from a differant location that has the same part number and see if the lights or clutch works. The fog light relay is located behind the rear seat back. You might be able to remove 4 nuts from inside the trunk and get the plastic panel to tip forward enough to get to the relay otherwise the rear seat bench and back will need to be removed....The a/c relay is located inside the engine compartment by the LF strut tower under the plastic cover. Hope that helps. Bill