98' Cav failed DEQ (emissions), crank and cam sensor codes.

[xFatcatx]

So my sisters 98' Cavalier, 2.2l auto, around 100k failed emissions the other week and is throwing codes P0335 and P0342 (i think, i dont have the codes in front of me at work right now) Crank and Cam sensors. After much headache I was able to replace the Crank sensor last night as that was the cheap one so I started with it. I am not sure if I correctly cleared the codes while doing it becuase both codes were still there when i ran to Autozone to get it scanned when i was done. They did clear the codes for me though after pulling them.

My plan now is to get it scanned again, and if the crank code is gone and the cam code is still there to replace the cam sensor ($80) tomorrow. If both codes are still there though I wasnt sure about replacing the cam sensor in case the issue was somwhere else. I did have a guy tell me today that the cam and crank sensors work together and if the cam sensor is bad it could cause the crank sensor to code also? I also got some advice from 2 different people that a loose "timing belt" (not to sure about this because it doesnt have a timing belt, just a timing chain) would cause those sensors to code also? I could do the timing chain but have never done one before so it would be a bigger job than normal for me. Anybody with any suggestions or knowledge about this would be appreciated.

For a while the car has been starting kind of odd. Its like it wasnt turning over, it would just all of a sudden start. Or it would turn over once or twice really slow, then start right away. That problem seemed to be solved after changing the crank sensor last night, on the first start when i backed it off the ramps it started up just like normal sounding good for the first time in a while, and continued to start well after that. Does anyone know what the crank sensor has to do with the car turning over? The check engine light had been on and off for a while, it was on when i backed it off the ramps last night, but did not come back on when we went to Autozone. No other symptoms besides these codes.

Thanks

[exalteduser]

if the light didnt come back on after changing it(crank sens), they likely just pulled non-cleared codes when you went back. looks like you may be good to go. just drive it more to see.

alot of times(not sure on this car but on my olds 3800) its not the sensor but the magnet (cam in my case) its attached in a plastic top hat shaped thing which you can see inside the sensor hole, it failed a ton on those engines, so if you get that crank code again, or cam code after changing that sensor if you do, thats something to look at.

as far as the 1-2 turns slow then starts right up, something as simple as a weak battery/dirty terminals can have that sort of affect

[J-Ri]

In most cases it's the cam sensor that's bad... the PCM needs the CKP sensor to run, the CMP just allows more precise fuel delivery and slightly quicker starts.

[xFatcatx]

Thanks, i couldnt log on here for a few days for some reason. Changing just the crank sensor fixed it, no codes now and it passed DEQ plus is starting great. Thanks

[Denman123a]

Originally Posted by xFatcatx

Thanks, i couldnt log on here for a few days for some reason. Changing just the crank sensor fixed it, no codes now and it passed DEQ plus is starting great. Thanks

thanks xFatcatx for reporting back after the problem was resolved, .. "I love it when a plan comes together" ....

[xFatcatx]

Originally Posted by Denman123a

thanks xFatcatx for reporting back after the problem was resolved, .. "I love it when a plan comes together" ....

2 days ago cel came back on and starting problems came back. havnt scanned it yet but i assume i will be changing the cam sensor next. will update when i do it, might be a little bit though im sick of working on cars at the moment.