I got a 1999 Honda Prelude for my first car, it ran great and there were no problems for a while. Then my engine light came on and it said I had misfires - random, cyl. 1,3, and 4. I replaced the spark plugs and wires and it was still misfiring. Eventually my car wouldn't even start and I replaced the coil and the distributor. It ended up being something with the cam shaft sensor, I had it taken to a place and they fixed that but I was still having misfires. I also found out that my car should be taking premium gas not regular [they lost the manual when I bought it and failed to inform me]. Recently, I had a code for catalytic efficiency below threshold and was told I needed a new cat. I replaced my catalytic converter and they cleared the code. After a little while the code came back on, I did not change the o2 sensors but I am being told I need to go to Honda and get my computer recalibrated which I don't really think makes sense. Any ideas why I'm having misfires or what I need to do in order for the catalytic code to go off?

 

Man, you already spent a lot of money on that problem.

There is a thread for this wrote by mgags and it's very helpful about this kind of problem.

I had same issue before w/ misfire and ended up it was just the valve clearance and that misfre code cleared. But just like yours, I also still have the catalytic code and I had the primary sensor replaced already. So, my second thought now is the seconday sensor (after cat) is bad.

 

haha yeah I've spent a lot of money of the course of a year. I read a lot of places your supposed to change both o2 sensors when you change the cat... But i was also told by a friend that works at a nissan dealer i might need to go to honda and get my ecu recalibrated because nissans need to.

I dont know what to do, either one would cost money so I don't want to do both unless i have to.

But as far as the misfires, thanks I have two new things to check for.



Modified by xdhp99 at 5:48 PM 4/13/2008

 

Yeah, just do easy stuff first before spending too much money on things that would not fix the problem. Check EGR and IACV and clean them as well as your intake manifold. Get a free service manual at hondahookup.com. I just follow the troubleshooting procedure on this when i had the misfire issue and the last thing I did was adjust the valves clearance.