Have a 2009 Honda Fit Sport with 5 speed MT. 110k miles give or take. Regular maintenance and basics taken care of on car.

Car began misfiring a couple weeks ago. Goes into safety mode and sputters to a stall at times. Pulled codes, cylinders 1, 3, and 4 misfire if I recall correctly. Don't have garage space so take it to the mechanic after reading on here about the coil issues and other possible solutions. 3 weeks later, new plugs, new coils, couple other things and problem is not solved.

Any ideas? Mechanic says possible ECU? Could bad fuel cause this issue? Clogged catalytic converter? Sensors? Just trying to check off some other obvious but simpler issues before breaking down and towing it to the Honda dealer.

 

First thing to replace may be the mechanic. Could be a lot of things but I would look at fuel trims and see if its lean or rich. Confirm spark.

Keep to the basics of fuel, ignition, compression/ timing. Once you find which one is lacking chase that.

Clogged cat will generally prevent the engine from going into high rpms.

Bad fuel can cause problems.

Dirty/bad MAF sensor. You could unplug it and see if it runs better.

 

+1 on replacing the mechanic 😂 I'm a B tech , I know not to jump straight to diagnosing a ecu 🤦 possible you have an issue with an load sensor, MAF or possible A/F oxygen sensor , ( the first one) this is just one possibility based on what you've said. But if you don't know how to really diagnose this I would say a tow to the Honda dealer is you're next best option, hope this helps.

 

I can't say anything bad about my regular mechanic. He's actually my neighbor and tried all he could. No dice. He only charged me $50 for labor in the end. So yesterday had the car towed to Honda. They wanted to take care of valve timing first and foremost. I reluctantly agree. They call today and say car is ready, go to pick it up, mechanics and service reps had already left for the day of course. Take it for a quick lap around the dealership and right back into flashing CEL, limp mode, and misfires.

Left the car there with a note since nothing was fixed and they clearly didn't make sure the problem was solved, just assumed it was after clearing the codes. Really starting to get discouraged, not trying to invest continuing money into an unsolvable issue.

Any other ideas?

 

I can't imaging why adjusting the valves was job 1; if the thing is suddenly stalling, misfiring on three cylinders then tweaking the valves is like putting lipstick on a pig. Adjusting the valves, confirming compression on all cylinders, replacing the spark plugs are great things.... to do after getting to the root of the problem.
Don't pay for that valve adjustment if that was not the problem. Their failure to properly diagnose the problem is an embarrassment to them, or it should be. They are Honda techs. If it's an ignition coil or the crankshaft sensor or whatever, they should be able to diagnose it. And calling it fixed and submitting it to you in that state? Unacceptable!

 

Should be clear. My mechanic did plugs, coils, checked compression, sensors, checked cat, to no avail. This is something more deeply rooted.

 

Sorry- I missed that part that the compression was checked and the coils replaced- though swapping out the coils for a known good one one at a time would have made better economic sense.. But if the compression is good, obviously the state of the valves and their timing are good enough to run the engine halfway decently. I still don't get why they insisted adjusting the valves of all things first. It will be interesting to see what they say when they take a second look at that engine.

 

Also keep in mind that just because a part is new doesn’t necessarily mean its good.

 

That sucks especially after taking it to the dealer. The only good thing is that they should spend a little extra time making sure things are done correctly the second time especially since they really screwed up the first time. I would make sure to talk to the shop manager and have them explain what the thought process was for their decision to do valves and then not even attempt to ensure things were done correctly. Not so much to throw it in their face or to be a problem customer, but just to emphasize you came to them in good faith and they dropped the ball. That might get you matched up with one of their better techs who will probably do a better job. On their defense, hearing that you the DIY mechanic or even worse, the neighborhood professional mechanic working out of their home garage is probably one of their nightmares as they would be much way better off if the car was brought to them in original problem condition. The amount of diagnostic work they are going to have to do just increased ten fold, and your risk of added cost just doubled as any parts your home mechanic replaced are going to be all suspect and recommended to be replaced. The caveat being that they were replaced with all oem equipment but even then still questionable because of who installed them.

I would give them a second chance with a little nudge of the inconvenience and then become a big PIA if they screw it up a second time.

 

So I’m curious as to what the outcome was. I’m having similar issues and would really help in diagnosing my problem.