Okay everyone, this has me perplexed. So my 03 neon SE is a 2.0 Automatic. With around 146k miles. I am the second owner. So first problem the car lost power going up a steep hill from a complete stop. Now I know it would normally not be flying up the hill. I did not have a huge load in the car. I was barely going up this hill I mean I was putting the pedal to the metal and nothing nada. Just plugging along nice and slow.

second problem occured after this incident. The car started shifting strangely after that. It would tend to go over the normal mph it would shift at before. I do not have an rpm needle in my cluster so I gauge the shifts my mph. For instance the car would seem to be boggy we shifting from 3rd to fourth. Instead of shifting at 35 mph like it did before it would go as high as 45mph before shifting. Now this is also acompanied by a higher revving of the engine.

Next item, when I first bought the car. I was pulling out onto a two lane highway. I had to cross one side of the highway to get into the lane that went the direction I needed to go. Now as I said I had just bought the car a day or two before this. So I am stopped at a stop sign waiting for my chance to cross traffic and then merge. So I see a gap small but big enough. I hit the gas the car goes but not fast it revs real high and shifts super hard into gear. With a big ka chunk. This almost got me t- boned. Now after this I did not do that again on purpose instead waiting for the big gap in traffic so I could baby it and gain speed steady instead of rapidly.

I listened this last one as last because I honestly do not mind driving like an old person. So I dI'd not mind the hard shift if I punched the gas and I just didn't do that. However with the occurence of the first two problems. I am worried I am working on it myself with my Cilton. I am a bit over my head.

what I have done is do my best to check the motor mounts. None of them seems to be broken. The steering wheel shakes a bit. On a cold morning it shakes quite a bit. I could not find the torque strut brackets to see if the bolts were broken or bent.

my check engine like is on and I checked my codes this is what I got.
PO551 CNF

PO456 CNF

P0456PND

​​​​​​​I looked all of these up and none of them seem to indicate anything about loss of power. Please help and thanks for reading this! And thanks double for responding.

 

How did you check the codes?

 

​​​​​​​I used what I think is called an odm 11 code reader plugged in under my dash by the brake pedal. I did not get these by using the key on off trick.

 

What's the CNF and PND you listed after the trouble codes? I'm thinking transmission issue, but you didn't get any codes, which is odd. Transmission is full of fluid? The fluid doesn't smell burnt? What color is the fluid?