Am I getting the run around. I went to three Japanese auto shops for them to diagnose my CEL. P0303 missfire cylinder 3. I have replaced sparkplug with oem ngk. I replaced ignition coil oem denso for cylinder 3. The CEL still appears.

Shop #1. I tell him what is wrong and what I have done and he checks the code. He suggested that I needed to replace the whole head. This is without any testing. I told him i'll be back and went to another shop.

Shop #2. Same code. He did a compression test show cylinder 1, 2, and 4 with 175 and cylinder 3 with 150. He suggested to replace the whole head. But he has never done one for a s2000 and was reluctant. I didn't blame him but I rather take it to someone that has worked on s2000's.

Shop #3. Same code. Supposedly did a compression test and found all numbers within range?. They suggested that I buy the other three coils instead of just one for the third cylinder. They suggested that buying all four new coils would fix the problem. I highly doubt this.

Does anyone recommend anyone in the DFW area that might help? My last choice is HONDA dealership. Any suggestions or comments are appreciated.

 

Are they resetting the ECU each time and it keeps reappearing after some time?
I would do a valve adjustment first then IF that doesnt work, look into injectors not functioning properly but more than likely I would bet on valves being out of spec. A honda dealer might not be that bad to look into.

 

Try cleaning the fuel injectors.

 

It sounds like it may be a compression issue. You need to have a good compression and leakdown tests done.

 

Do a leakdown test on cyl. 3. It will tell you if your intake valves or exhuast valves are bad or bad piston rings.