2001 Saturn SL2 EVAP code P0452

Checked all connections. Everything is good (except the purple wire to the starter but that is irrelevant to the evap system). I have suction from the throttle body to the EVAP solenoid but no pressure or suction from the tank. I put pressure to the tank with an external air hose and the only place I could hear or see it come out (smoke test) was by the gas cap with the cap off, no visible pressure release with the cap on. There has to be a leak by the canister even though I cant find it.

I am now also getting error P0405 and P0404 and a surging while I am driving. So in addition to the Evap system I probably have a bad O2 sensor or EGR problem. OH JOY!

The 452 error started last winter when a Chunk of asphalt kicked up and streached the fuel line and tore the evap line. I replaced the fuel line and bridged the evap line. I keep saying I am looking for a leak because of this. I have already replaced the EVAP selonoid because when the hoses pulled it broke the unit off of the bracket. I also double checked (and triple checked) the wires in the area of the selonoid. I droped the gas tank and could not see any signs of damage from the pull. Where is the other sensor or wiring harness I should replace/check.

Today I pulled the EGR valve and attempted to clean it. It did not seem to stick but it was carboned up a lot. The car is still surging so I may grab one from a junk yard to see if ireplacing it makes a differance.

I am about ready to take it to a shop and let someone else give it a shot. With 170k on the car and all the other minor problems added in, I just cant justify droping a lot of money to fix it. If it were not for NJ inspection I would just drive it utnil it dies.

Thanks Aain for the info.

I am not arguing either. I agree that it is electrical. There is a low voltage issue at a sensor related to the evap system. That is why I repalced the EVAP soleniod on the motor. I am using the work leak but I understand that it may be that a sensor, related to one of the lines that got pulled, took a wack and is not functioning. I am out of Ideas of what to look for and where. There is suposed to be a sensor on top of the gas tank and I did not see it when I pulled the tank the last time. When I am down to empty again I will drop the dank one more time. If I cant find a problem again I will just replace the tank, lines and sensors with one out of the junk yard.

I have been reading what you sent me. I hate to admit that when it comes to electrical I am at a bit of a disadvantage, I have a multimeter but only have the basic knowledge of how to use it. I am a back yard mechanic. I can rebuild a motor or bread system in record time but when you put a circut diagram in front of me it takes me a while to figure it out and then only if im lucky.

Picture a realy smart monkey then put a set of glasses on him and add a test light, that is me when it comes to computer controled electronics.

See next post. Corected information with new more detailed.

I checked and I have 4.98 v at both color coded terminals. I am assuming that the white wire (terminal A) is ground. From what you have told me this should not be the case. These wires must be contacting somewhere? One should be a signal from the computer at 5v to the sensor and the other should be the return signal from the sensor to the computer?

Had continuity between terminal A & B with key off. Also had continuity between A (orange and black)and body (makes sense, think that is the ground) and B (green) and body. Could not find a break in the harness but after moving the harness and testing at the junction block by the kick pannel I now do not have continuity and I do still have 4.98 on terminal C (grey). When contacting A & B or B & body I get a fluctuating #, not O.L for continuity. Being I can not find a break and the orange & black does not go all the way forward I would think I could just abandon the existing wire, reground terminal A to the body and run a new green wire from the junction block. I will wait for a response before I burn out the computer or something.

If we solve this problem and I dont have to replace the car I will deffinatly make a "donation". I know you have helped a lot so far and it may not be fair to say payment is depending on outcome but I dont have any extra money if I have to replace this thing. Regardless you have my thanks.

I understand that these are seperate and should not cross at any point. I will follow the harness as far as I can. There is no orange/black wire at the junction block by the kick plate. Do you know where this wire splits off from the main harness. If I can not find a break or exposed spot on the wire I will just run a new green wire from the junction block to the plug then cut the original wire at both ends.

If the orange/black wire is contacting somewhere it should not matter once the other wire is disconnected.

Should I replace the sensor, since the wire was shorted, while I have the tank out

I traced all the wires and could not find a break anywhere. I disconnected the wires from the computer and jumpered the gound to the other two wires one after another (after ensuring I had a good ground with the computer disconnected) to verify that I was working with the correct wires by the fuse block. Removed jumper, reconnected plugs to computer and ran a new green wire. Checked voltage at Terminal C. 4.98, B nothing, A ground. Reinstalled the gas tank and started the car. Ran for about 30 seconds and the check engine light came on. I will get the reader this weekend and verify it is the same code but I am sure it is.

If you have another idea I will give it a try but I think the car is done.

Thanks for trying

Still code P0452. EGR Codes did not come back. I will have someone with better equipment plug it in and see what they get. A and B have continuity again. When I get it to break continuity I still get a fluctuating # not 0.L. Think this indicates that there is something jumped in the computer but I will still get someone to plug it in and verify.

Thanks