I have a 96 protege with a 1.5
The car has been running ruff the past few weeks. The check engine light has came on, so i took it to autozone and had it checked and the code that showed up was P0301, Cylinder 1 misfire. I have recently changed plugs, and wires along with cap and rotor. Also I put on a new fuel filter and have ran several test to check for vacuum leaks and have came up with no leaks. I recently put a new muffler on the car to but i wouldnt think a new muffler would cause this! as for it was a stock replacement one.

Any Help or advise in where to check next would be great!!

 

Is it still misfire? if so, injector is the issue.

 

Yes as of right now it is still misfire on cylinder #1. I am going to pull the plug and check it. Thought that maybe since I wasn't running a muffler and now I have a new one installed maybe the car is getting the back pressure again and caused the plug to foul out. Just a thought!!

Whats the best way to clean an injector if that may be the problem. Run injector cleaner in the tank? or maybe try a can of seafoam threw the vacuum lines?

 

You might try injector cleaner, also don't use crappy gas in the future. If you can get to it with a tool to tap it with it running, it could be something stuck inside it. I've had that issue before. If the plug is fouled, I'd say injector, and fuel filter replacement.