Hey everyone! Not only am I new to this forum, I am also new to being a Saturn owner. I picked up a 99 SL2 automatic back in May 2013 and only drove it about 2 weeks before it gave me problems. Love the car and I would love to get some valuble knowledge from you guys. Ive been reading forums off here and it has been helpful, somewhat. Below I am going to explain whats wrong and what has been done to the car.

Ok, The car runs perfect in Park and Neutral (around 1000) but when I put it in reverse and drive, the idle is all over the place. It sounds like it wants to stall on me. We have installed new spark plugs and wires (they are wired to the right configuation), Ignition coils, injectors, EGR valve, TPS sensor, even the coolant sensor (the flat nose brass one). I even had the fluids flushed, when I felt safe enough to be on the road. We checked the transmission solenoids and they were in the right ohmn range. when we hook it up to a code reader, P0340 and P0300 pop up. the definition says its for the cam shaft position sensor, but through many people, that doesnt exist on the car. Help? I am starting to run out of ideas! Thank you so much for reading this! Im also sorry if i posted this in the wrong area, Im new to forums also!

 

Welcome to the forum. When you replaced the coolant sensor, where did you purchase it? If it's not from a GM dealer that sells Saturn parts, odds are that's still a problem for you. They're not calibrated correctly in the aftermarket world. Also, have you cleaned the throttle body? and did you clean the EGR passage on the intake when you replace it? You don't have a cam sensor, but you do have a crank sensor. I think they run about 15-20 bucks at Autozone. GM will probably be higher, but a better place to get it if you decide to continue shotgunning parts and hoping to clear your problem.

 

Oh thank so much for your response. We did pick up an aftermarket coolant sensor, so I will def keep that in mind on going through the dealer. We (as in my bf and myself) have been picking through all the forums with this problem and cleaned everything out, and still no dice. I forgot to mention in my original post that I did replace the crank sensor and fuel filter. The last month has been parts overload trying to get this up and running safely, so i apologize for parts i forgot to mention! Through the entire adventure of figuring the problem out, we have cleared the original codes that have been popping up but I keep getting asked if we are going through a "reverse slam" and the way its been described to us, our response has been kinda sorta, its not super violent but I really cant sit at a light in drive or back out of a parking spot without it wanting to stall. I will def take your advice and even clean out the areas again, just in case we missed a spot. Thank you so much again and I will leave an update when something improves.

 

When you go to a dealer, make sure they still sell genuine Saturn parts. In addition to the electronic coolant temperature sensor (ECTS) get the wiring pig tail too. They've been know to be problematic too and if you're going to do this, you need to do it right and not half-*** it.

 

Will the coolant sensor be the problem if the car now only wants to stall when brakes are applied?

 

If the car is stalling when you apply the brakes - you have a vacuum leak

 

You weren't clear about the stalling part in your first post. If it acts like that when stepping on the brakes, then I have to agree with Mike. You have a vacuum leak. The first place to check is the brake line running from the brake booster to the engine. IF your Saturn has a check valve, it could be defective. Here is a link from Autozone that shows what you're looking for. It's in the second picture. The part with a nipple on it.autozone.com/autozone/accessories/Miscellaneous-Repair-Parts/Power-Brake-Booster-Check-Valve/_/N-25pd?filterByKeyWord=power+brake+check+valve&fromS tring=search

 

Thank you very much, It wasnt clear to us either that when the brakes were applied it would stall. it felt like it would stall in reverse or drive, but that wasnt the issue. again thank you for all the help!

 

Do us all a favor and be sure to post back if you get the problem solved and let us know what worked. Nothing pisses us off more than trying to help someone and never hear from them again.

 

The camshaft position sensor is a capacitive plate underneath the 1/4 coil. As far as I know, it doesn't usually cause any problems. Usually the problem is a defective sparkplug or sparkplug wire, but you have replaced those. I hope you did not use any low resistance wires, they must have the correct resistance to work. I am on the road again, if you haven't fixed it by the time I get home, I will look up the troubleshooting procedures for the code P0340. The P0300 can be the result of the 340 or the other way around.