More trouble codes🤦🏻‍♂️

[FL5ghost]

Unfortunately today the car threw a flashing CEL and then went away. I checked my flash pro and boom not 1 not 2 but 3 trouble codes… P0300, P0304 and P0301. A couple of days ago I was dealing with a P0302 trouble code which I cleared and the car was driving fine. I cleared these 3 codes and did 3 back to back redline pulls and the car feels fine as it usually does. What could this be from? Do i have a bad tune?? This is starting to become concerning.

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[TypeRD]

Might be valves too tight out of spec. I was getting misfire codes too. My car drove totally fine, but threw a random CEL twice (MANY miles passed between them). They thought it was electrical at first. I thought for sure it was the solenoid issue. Nope on both accounts. After the 2nd CEL they called the Honda Tech Service line. Turned out my valves were slightly out of spec (too tight) from the factory. Since they corrected this I’ve had zero problems. No CELs.

You might consider not simply clearing your codes and letting the car rip…though, it seems you’re trying to avoid warranty work since you have a tune?

 

[FL5ghost]

Might be valves too tight out of spec. I was getting misfire codes too. My car drove totally fine, but threw a random CEL twice (MANY miles passed between them). They thought it was electrical at first. I thought for sure it was the solenoid issue. Nope on both accounts. After the 2nd CEL they called the Honda Tech Service line. Turned out my valves were slightly out of spec (too tight) from the factory. Since they corrected this I’ve had zero problems. No CELs.

You might consider not simply clearing your codes and letting the car rip…though, it seems you’re trying to avoid warranty work since you have a tune?

Well, I'm FBO with a MHI stage 2 Turbo. If this is the issue then this is concerning. This just started happening As well.

 

[Jester04]

Well, I'm FBO with a MHI stage 2 Turbo. If this is the issue then this is concerning. This just started happening As well.

Send me a DM, I will try to help you.

 

[TypeRD]

Well, I'm FBO with a MHI stage 2 Turbo. If this is the issue then this is concerning. This just started happening As well.

Yeah, minor misfires happen all the time. That’s totally normal and are accounted for. But misfires that are significant enough to throw a CEL are definitely more concerning. This doesn’t mean any damage was done, but you definitely want to get it taken care of ASAP.

 

[Jester04]

Yeah, minor misfires happen all the time. That’s totally normal and are accounted for. But misfires that are significant enough to throw a CEL are definitely more concerning. This doesn’t mean any damage was done, but you definitely want to get it taken care of ASAP.

Most of these codes pop at startup. They are there from a initial cold start. Most of the time they are not a problem unless they happen at a wot pull.

 

[TypeRD]

Most of these codes pop at startup. They are there from a initial cold start. Most of the time they are not a problem unless they happen at a wot pull.

My CEL’s were at startup too. Though, what’s weird is that they showed up on my 2nd or 3rd startup while running errands. The car had initially warmed up and hadn’t cooled all the way back down when I restarted the car the 2nd or 3rd times.

Even though the codes popped at start-up, it’s definitely not good to thrash the car with valves that are too tight, right? Probably why the car goes into limp mode…to prevent major damage, yeah?

I’m not an expert. My questions are actual questions…which might pertain to the OP too.

 

[Clark_Kent]

In the last week on this forum and the other one I've noticed a collection of posts with folks experiencing persistent CELs. The common denominator is all of the cars are modified. Keen to know how these get resolved.

 

[Jester04]

My CEL’s were at startup too. Though, what’s weird is that they showed up on my 2nd or 3rd startup while running errands. The car had initially warmed up and hadn’t cooled all the way back down when I restarted the car the 2nd or 3rd times.

Even though the codes popped at start-up, it’s definitely not good to thrash the car with valves that are too tight, right? Probably why the car goes into limp mode…to prevent major damage, yeah?

I’m not an expert. My questions are actual questions…which might pertain to the OP too.

Well if the valves were that tight to cause any issues with very little mileage that would be a concern.

 

[TypeRD]

Well if the valves were that tight to cause any issues with very little mileage that would be a concern.

First CEL happened at about 1700 miles. Second one happened at about 2700 miles. Dealership said they found that 2 of the exhaust valves were just a little tight, and I think maybe 1 intake valve was slightly tight too, iirc. They weren’t extremely out of spec, but apparently juuuust enough to pop the CEL’s. It was the exhaust valves causing the misfire codes on startup.

It has been said that these cars’ sensors can be pretty touchy, especially during the first few thousand miles. I think that’s probably true. It seems that maybe too many modifications too early in the ECU’s learning process could exacerbate things. I’ve noticed that most of the experienced folks here who are modifying their cars take a very methodical approach. One modification. Test. Tweak. Another modification. Test. Tweak…and so on

 

[Jester04]

First CEL happened at about 1700 miles. Second one happened at about 2700 miles. Dealership said they found that 2 of the exhaust valves were just a little tight, and I think maybe 1 intake valve was slightly tight too, iirc. They weren’t extremely out of spec, but apparently juuuust enough to pop the CEL’s. It was the exhaust valves causing the misfire codes on startup.

It has been said that these cars’ sensors can be pretty touchy, especially during the first few thousand miles. I think that’s probably true. It seems that maybe too many modifications too early in the ECU’s learning process could exacerbate things. I’ve noticed that most of the experienced folks here who are modifying their cars take a very methodical approach. One modification. Test. Tweak. Another modification. Test. Tweak…and so on

interesting and good to know! I have seen stock cars pop up some codes also but its really hit or miss. Mine did these codes 2 times in cold startup and then they went away and never came back. So it really is something I can’t fully explain.

 

[HondaFan777]

Get a resolution?

 

[HondaFan777]

Curious because I am getting ready to buy MHI Stage 2 Turbo

 

[Integra23]

Curious because I am getting ready to buy MHI Stage 2 Turbo

Im running the MHI 2 without issue and tuned by @Jester04.

Once your run more boost you need to change your spark plug gap. I am running the Ruthenium HX plugs gapped to 0.020"

 

[HondaFan777]

Im running the MHI 2 without issue and tuned by @Jester04.

Once your run more boost you need to change your spark plug gap. I am running the Ruthenium HX plugs gapped to 0.020"

appreciate it.

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