Hey Guys I'm New To The Forum, I Have A 97 Monte Carlo LS With A 3.1 Engine My Parents Parked It In The Garage For 5 Years After The Head Gasket Blew. I Made It A Mission To Restore & Mod . The Head Gaskets Were Just Replaced But The Engine Light Is Still On I Feel Like Im Not Getting Enough Power & Overheats Even With New Thermostat. Any Ideas Of What Is Causing The Problem?

 

did you get the code read? whats the code?

 

1. - What is the code number causing the light?
2. - When you did the head gaskets, did you completely clean the deck of the heads AND inspect that they were not warped??

 

3 Codes Came Up

1 - P1406 - EGR Valve
2 - P0122 - Throttle Position Sensor
3 - Random Misfire

 

yes, nothing was warped. some friends say i need a new catalytic converter as well..

 

Car sat for 5 years. Check all the hoses, make sure everything is in tact, make sure nothing was eaten, or rotted.

Did you drain the tank, change all fluids, etc.

 

Before I discuss what I looked up, I think Chibi picked up a good one. Check for "critter" damage. Also, if you did not put any fuel stabilizer in the tank it may have been "gumming up". This will cause bad performance. Basically, you can either let the car burn the old gas or get it out of the tank. Once the tank is empty, I would change the fuel filter (the element in it is probably all full of crud, but I would not change it until you address the gas in the tank, avoid sucking in more bad gas on a good filter). Put fresh gas in and give it a bottle or two of fuel system cleaner (I don't swear by the stuff, but it's not going to hurt). The car might have "gummed" up injectors too and the cleaner may be of help (heck if you choose to burn off what's in the tank, drop a bottle of cleaner in with it).

Check for vac leaks and bad wiring. As for a possible bad cat.... Let the car run and after it's ran for say 5 minutes, look under it at the cat. If the cat is bright red, it's bad (or you have something stuck in the exhaust. Normal operation you won't notice a coloration change of the cat.

Now, I looked up the codes and here's some points of reference from the shop book on each (well 1 and 2). There are far more details then what I have hear.
1 - P1406 - EGR Valve
Important: If the EGR valve shows signs of excessive heat, check the exhaust system for blockage (possibly a plugged catalytic converter) using the Restricted Exhaust System Check.
- Check for xcessive deposits on EGR valve pintle or seat. Check for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.
- Poor connection or damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the EGR actual position display on the scan tool while moving connectors and wiring harnesses related to the EGR valve. A change in the display will indicate the location of the fault.
I know the 3100 has a tube between the EGR and UIM that commonly gets gunked up (at least with the old analog 3 solenoid EGRs). I'd pop the EGR off, use some carb clean on the EGR itself (resting it upside down to let is soak in a little) and then I''ve used Carb Clean and a piece of old speedo cable to shove into that passage on the UIM to clean/dislodge any "gunk".
2 - P0122 - Throttle Position Sensor
Basically, the book talks about checking the wiring to the TPS and how to check it. I believe you can test the TPS itself with analog (NOT digital) volt meter. Using the voltmeter you are watching to see if the TPS gives a reading as you move it's position by hand (I had to do this years ago on a '93 Grand Am).

3 - Random Misfire
As for this code, what was the actual code? Some link to a specific cylinder other's it's all random which cylinder.

Hope this helps. I really think the old gas is a BIG part of the problem.

 

Thanks guys I will have a update by Friday

 

Random misfires are sometimes caused by a fueling issue.

 

over heat issue i am suprised that no one asked, did you blead the cooling system to get all the air out?
missfire, plugs and wires new?

and like said above check for critter evidance