Engine "Stumbling" Issue
 

I've got an 04 accord, 4 cyl, manual. About 115,000 mi.

The car seems to be "stumbling". I could be doing 80 on the highway or sitting at a stop light. By stumbling.....kind of a skip. After plugging it into the OBD reader, I'm being told Cylinders 1,2,3, and 4 are misfiring and it's bringing up an rear oxygen sensor error, which i've changed recently and there were no issues after that (i was told the ox sensor is coming up because of the misfiring).

So, what can be the problem. Any ideas? Thanks a lot

Also, it "stumbles" right after starting the car and after driving for a while.

How about your spark plugs? How old are they & what brand? Honda seems to like NGK the best.

I changed the plugs about 20,000 miles ago. I put platinums in which is what honda calls for. Took a look at them recently, they seem to be fine.

NGK? People have reported misfiring using Bosch plugs.

Bosch makes junk iginition parts. Even VW doesn't recommend them

That's why I'm trying to get Spartan to say what brand - not just "platinum".

Well.....sorry for the delay. I do not remember which I put in there. Could have been Bosch. Could have been NGK. I'll have to check. But why would all cylinders show misfiring at the same time if it's plugs? All four plugs fouling at the same time?

If you replaced all 4 plugs with the wrong ones (it's debatable whether Bosch is "wrong") then all 4 would be misfiring occasionally.

I've used Bosch Pt+4 in a 95 Integra without problems, but MANY people have reported problems with them. So I'm just suggesting that as a possibility.