I have a 1994 nissan maxima, manual, and it has given me little trouble until recently. A couple months ago the check engine light began to come on but only at higher rpms like 5000. It’s not crazy high, but i guess that is a matter of opinion. I didn’t reach that point often but it started to worry me when one day while driving on the highway I seemed to hit a piece of debris on the road. I don’t remember seeing anything in front of me or I would have avoided it so I think it fell off my car. Either way it got kicked up and banged the underside of my car and immediately after that my engine doesn’t seem to engine brake at all and my performance has dropped as well. In addition, the check engine light that came on before at 5000 rpms now comes on at around 3000. I’m really puzzled and didn’t want to take it in to see a mechanic. If anyone could help me with any ideas or tips that would be great.
You need to have the error codes checked first. Places like Autozone will do that for you. Let us know what the codes are and we can go from there.
The auto parts store may be able to pull up a code; but, if they only use a CODE READER, and the check engine light isn’t on at that time, they won’t get anything.
Raise the car, and look at the underside. There may be damage.
OOPS! I had a good answer; but, it was for someone else’s question. So, I erased it.