finally got my gp

hi all. thanks for all your help with my questions. good news i finally got my grand prix. its a 00 gtp. I got it last week, and im very happy with it.a few days ago the check engine light came on. I checked everything i could think of and unplugged the battery to try to reset the computer. nothing helped. i was a bit nervous at this point, although everything felt fine. as i understand lemon law would force the previous owner to pay for repairs anyway.anyway, i took it to a local shop to get checked out. as it turns out the code was for slow gas evaperation, which was caused by debris in the threads of the gas cap. im glad it was nothing major, but still feel screwed being charged 60 dollars for nothing.now for the questions. i was told the computer cant be reset by disconnecting the battery, is this true? Also i read elswhere about buying a scanner, how much are they, and what brands do you recomend. finally what kind of gas milage should i be averaging if everything is working properly? thanks for all your help eveyone!

Actrons are a good bet for a scanner....100-300 investment

Should get 27 or so on the hwy.....

I am not positive it works on this model....but I think you can pull the positive cable and then go hold the ignition switch in the start position for about a minute and it will reset the computer......then go back and reconnect the battery...... Someone else will chime up....and verify this is true or not

I agree with Ernie. The Actron is good all around brand and reasonable cost. I have a Superscanner CP9145 for the big jobs and more detailed analysis and the smaller code reader CP9125 for the small. The CP9125 works great just to get a fast readout on generic odb-ii codes and to reset the SES light. Cost around $60 or less.

go with the scanner. i am pretty sure that there is no DIY way to reset the check engine light. depending on the code, you can fix the problem, and the light will go off. i had the check engine light for "MAF irregular voltage", i fixed the prob, and the light went off itself. with the newer vehicles, the code is stored in the computer, so it does not work to disconnect the battery. its like unplugging your pc or laptop, when you turn it back on, everything stored in the memory is still there. on my friends 95 taurus, it works to disconnect the battery, but your 00 gtp is too new for that. another option outside of getting the scanner is to find out what the code is at Auto Zone, post it here on the forum, and someone will help you find out what it is and how to fix the problem. then you can go back to AZ and have them clear the code.
as far as gas, i get 19-22 in the city, 29-32 on the highway, in my 01 gt. yours should be similar or a little lower with the supercharger.

thanks all. when i first got it i was getting 17mpg. i ran some lucus injector cleaner though it and im now at 20 mpg.still not what it should be. i havent tested much yet such as o2 sensor or injector flow, i wanted to diagnose a bit more with a scanner.i know the next questions, so i will answer them now. i am using premium, i do have a lead foot, but i havent been using it. all miles are almost the same, to and from work 90% highway cruising speed 75 - 85 mph. the ride feels excellent, no hesitation or rough idle. the trans feels like its not sure what gear it wants to be in at around 40mph and about 20% throttle, but i may be paranoid, cause what im used to is the gn with a commanding shift kit which slams into each gear and lets you know when it wants to shift.the gas cap looks good which confuses me about the check engine problem.any ideas. also, the exaust fumes are visable, but dont look smokey at all.im planning on changing the air filter and switching to synthetic all around.im trying to decide if i should change the wires and such, or the injectors.which in guessing should be about 28-32gph.i was gonna shoot some throttle body cleaner through it, but i concerned as to whether or not it will affect the blower.. any knoladgable suggestions will be greatly appreciated. thanks again

thanks all. when i first got it i was getting 17mpg. i ran some lucus injector cleaner though it and im now at 20 mpg.still not what it should be. i havent tested much yet such as o2 sensor or injector flow, i wanted to diagnose a bit more with a scanner.i know the next questions, so i will answer them now. i am using premium, i do have a lead foot, but i havent been using it. all miles are almost the same, to and from work 90% highway cruising speed 75 - 85 mph. the ride feels excellent, no hesitation or rough idle. the trans feels like its not sure what gear it wants to be in at around 40mph and about 20% throttle, but i may be paranoid, cause what im used to is the gn with a commanding shift kit which slams into each gear and lets you know when it wants to shift.the gas cap looks good which confuses me about the check engine problem.any ideas. also, the exaust fumes are visable, but dont look smokey at all.im planning on changing the air filter and switching to synthetic all around.im trying to decide if i should change the wires and such, or the injectors.which in guessing should be about 28-32gph.i was gonna shoot some throttle body cleaner through it, but i concerned as to whether or not it will affect the blower.. any knoladgable suggestions will be greatly appreciated. thanks again

How many miles are on it? With 90% highway you should be doing better on gas mileage. If you are uncertain about the maintenance history do a tune up. Start with spark plugs and wires, fuel filter, air filter, pcv valve, etc....the easy stuff. Stay with AC Delco spark plugs and the Premium Silicone 7mm wires if you are stock.

On the use of throttle body cleaner such as products like STP TB spray cleaner it is not a good ides to use the stuff while engine is running. You may damage intake seals/gaskets. You can clean the throttle body on or off the engine. Clean the MAF sensor hot wire element with electrical contact cleaner. Also, remove the IAC valve for cleaning. Spray the pintle and seat where the air orifice is located.

02 sensors can get carboned up and may reduce fuel economy so it is a good idea to remove them and clean with the TB cleaner. Make sure you can see light between all vanes on each sensor. 02 sensor may not trigger a SES light or set a DTC error code until they get below 60% efficiency.

BTW - Switching over to synthetic motor oil like Mobil 1 Syn is a good idea. But I would excercise caution using synthetic ATF in the tranny this late in the ball game. It has been known to cause clutch slipping once mileage has been accumuated.

very helpfull advice. at least now i have a staring point. as far as the check engine goes, it is po442 which im told is a small evaporation leak somewhere in the fuel system. the shop that scanned the code said they found debris in the threads of the gas cap. it was cleaned and reset, the code was gone for about 2 days. i wanna check the egr system, but havent had a chance yet. then the strangest thing happened (strange to me but technology is new to me, 87 is anciant to 00). I went to start my car and nothing happened, seemed like the battery died. on the second try it started right up, no slow turn over, no dim lights. once it started, the check engine was gone. anyone know what thats about?