Misfire codes keep coming back
#1
Misfire codes keep coming back
I recently bought a 2003 CL S-Type 6-speed w/ 68k miles. About a month after driving it, the CEL came on and stayed on. I took it into a shop that specializes in Hondas and had good reviews on the internet. The codes were misfire codes on all cylinders along w/ a bad O2 sensor. They changed the O2 sensor and figured that was somehow causing the misfires ($220 total to replace). About 150 miles later, the CEL came back on and I took it back in to the shop. This time only the misfire codes were present (P0300-P0306). They said that it could be the EGR, so they cleaned it and I noticed an increase in power ($95 to clean). I've always used only 93 octane gas at Amoco, so I told them that's not the problem when they asked what kind of gas I'm getting. Around 100 miles later the CEL was back on. Once again the codes were P0300-P0306 and the shop owner said that it might be the spark plugs, though they should last over 100k miles. To replace all 6, it cost ~$250. The CEL came back on within 25 miles (I was shifting from 2nd to 3rd when I noticed it came on). The shop owner then recommended I leave it for a few days so they can drive it. I left it there for 5 days and they came to the conclusion that the problem was with the fuel injectors. They told me that two of the injectors were within spec (though on the low end), but they said were leaking fuel because 1) the light didn't come on when it was driven aggressively, and 2) a small fire shot out when they were checking the engine combustion which definitely should not have occurred (~$440 to replace the two fuel injectors). I was in disbelief when the CEL came back on as I was pulling out of the shop (when I shifted from 1st to 2nd gear)
I've completely lost confident now in that shop, so am planning to take it to another shop that has good reviews and also specializes in Hondas. I've read that these codes are hard to diagnose, but I feel like I've spent $$$ for things that I didn't even need and didn't fix the problem. Has anyone seen this before? If you guys have any advice I would greatly appreciate it. I love the car, but you can imagine my frustration at this point.
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#3
Yea, I think so too. The only similar thread that I've found said that replacing all 6 of the fuel injectors fixed the problem (spark plugs nor cleaning the egr did not fix the problem in that case either).
This morning the CEL went off and hasn't come back on after about 50 miles of highway driving. I'm debating as to whether to wait and see if it comes back on before I take it to another shop to get it looked at. Is it normal for the CEL to go off before checking the codes?
This morning the CEL went off and hasn't come back on after about 50 miles of highway driving. I'm debating as to whether to wait and see if it comes back on before I take it to another shop to get it looked at. Is it normal for the CEL to go off before checking the codes?
#5
I was hoping the cause for the CEL might be a loose gas cap, but that ended yesterday morning. A little over 3000 RPMs in 1st gear the car jerked forward and the CEL came back on. The car jerked again at around 3000 RPMs in 2nd gear. It was really cold yesterday morning and when I started the engine it wasn't idling smoothly (gave it a minute to warm up). I'm taking it into the shop this morning
I'll ask them to check the coils... I don't know what else it might be, unless the codes are different.
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#6
The codes included the usual misfire codes, but also a VTECH code. The mechanic replaced a connector at the VTECH oil pressure switch. He showed me the old one and it looked like one of the terminals was recessed. The faulty electrical connection for VTECH would explain the jerking at the higher RPMs that I wrote about in the previous thread.
The next morning (<20deg F) I'm letting the engine warm up at idle and after a minute the CEL comes on and has stayed on for the last few days.
I set up a time Monday morning to take it back to the shop. The odd thing is I notice no problems at all with the car when I drive it since the VTECH connector's been replaced. I guess we'll see what the new codes are, but my hunch is that they'll be misfire codes on all cylinders. Maybe the coils. How much would that cost? Do I need it if the car seems to be running fine?
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#7
The shop owner called his friend at a dealership and they said swapping out the EGR for a new one fixes 90% of cases like mine. He had a used one he's letting me borrow for a week to see if that's the problem. If the CEL doesn't come back on, parts & labor for an EGR kit should run around $175.
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#8
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After a new EGR didn't fix the problem, I took the car to my local dealer at the recommendation of the independent shop owner. They had it for several weeks, knocking their heads against the wall as to what it might be. They heard from other dealerships that doing a valve adjustment solves the problem (usually not required until 110k miles). So that's what they did and the misfire codes haven't been back since. The best part is they didn't charge me a penny for it! They told me if the valve adjustment didn't work, the only other possibility was a bent valve... needless to say, I'm glad the valve adjustment appears to have fixed the problem.
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#12
Originally Posted by gtg975n
After a new EGR didn't fix the problem, I took the car to my local dealer at the recommendation of the independent shop owner. They had it for several weeks, knocking their heads against the wall as to what it might be. They heard from other dealerships that doing a valve adjustment solves the problem (usually not required until 110k miles). So that's what they did and the misfire codes haven't been back since. The best part is they didn't charge me a penny for it! They told me if the valve adjustment didn't work, the only other possibility was a bent valve... needless to say, I'm glad the valve adjustment appears to have fixed the problem. ![Thumbs Up](https://acurazine.com/forums/images/smilies/thumbsup.gif)
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