Help! No one can figure out this issue

[integra__gang]

I’ve been tryna find what is causing this issue for the longest with no luck! Car has rough idle, and start ups. I’ll attach a video
It also throws misfire codes on start up. The problem is more noticeable on pump gas and e-mix compared to straight e85, pretty much on only ethanol the idle is better but if I add gasoline to the mix the idle gets rough (rough start/ long cranking is always there no matter the fuel type) I also got this idle code p0507 a few times thinking there was a vacuum leak and I did find my catch can hoses to be brittle which I replaced but it’s still causing it.
I even used a smoke test and there’s no vacuum leaks except for the one I replaced the hoses on the catch can.
the car drives perfectly fine but it’s got to the point where it’s so F-ing annoying having to deal with that and I don’t know what is causing it. I even changed spark plugs and swapped coils with my friends FK8 type r with no noticeable difference. I just don’t want to spend any more money on it without knowing if it’ll solve it or not, I’m just guessing at this point.

this is my mod list;
PRL high flow intake
PRL charge pipes
PRL intercooler
Catless downpipe
Front pipe
Hondata’s CANflex fuel sensor
Flashpro/jailbreak
Catch can

If anyone has has this issue and solved it please help, I can’t find any one else that has had this issue before.. btw my car has 28k miles.
Also the website isn’t letting me upload the video I’ll try to upload it as a reply to this thread

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[integra__gang]

Here’s the video of the cranking and start up, I’ll try to get another video of the idle when I pump gasoline

 

[StingertimeNC]

Time for a custom tune? Who's tune are you running?

Also I would just get rid of the catch can. I've seen at least one vid that it's more of a pain in the ass than it's worth.

Anyway, If you haven't talked with @JesterTuned, I would hit him up. he'll give you the scoop on the catch can, etc. He's great to work with and probably the most affordable tuner.

 

[integra__gang]

Time for a custom tune? Who's tune are you running?

Also I would just get rid of the catch can. I've seen at least one vid that it's more of a pain in the ass than it's worth.

Anyway, If you haven't talked with @JesterTuned, I would hit him up. he'll give you the scoop on the catch can, etc. He's great to work with and probably the most affordable tuner.

I just have the hondata e85 base tune, you really think it’s the tune? I was driving with no issues until recently it started doing that when I installed intake, charge pipes, intercooler. That’s why I thought it was a vacuum leak, I’ll ask him hopefully he has some insight

 

[StingertimeNC]

definitely think it's the tune and maybe the catch can too! If you pull a log, then send it too him he can see what's going on. Probably just needs a few tweaks.

 

[elh0102]

I'm an old fart who has been through many cars with various degrees of mods. My 2025 Integra S is bone stock and will remain so. As others have suggested, your best bet is to find a tech who is competent with your tuning. The factory spends a ton of money on engineering these cars. In my experience, when you think you know better, you're mistaken. Good luck.

 

[Victorofhavoc]

definitely think it's the tune and maybe the catch can too! If you pull a log, then send it too him he can see what's going on. Probably just needs a few tweaks.

Does the catch can keep the factory pcv valve or replace it? If it replaces it then you're relying on the can to seal for you when it needs to. If keeping the valve then it should be a nonissue.

When you're running higher e concentration does your car ever sit for a while to where it might evaporate some? It sounds like the fuel pump is struggling to deliver or maybe the injectors aren't providing enough fuel. Either way, log and have someone review. Best bet is to find someone willing to teach you along the way so you know how to diagnose yourself later.

 

[StingertimeNC]

I believe the catch can is inserted into the system via existing hoses. The existing PCV valve stays in place as far as I know. I'm not exactly sure on this car, but on my previous car I just couldn't get the hoses to seal up tightly so the vacuum leak code continued to come up, so I finally removed it.

@Pointbypatrol mentions removing his catch can for some reason or another in his most recent video.

Either way, the tuner should be able to sort it out.

 

[Victorofhavoc]

I believe the catch can is inserted into the system via existing hoses. The existing PCV valve stays in place as far as I know. I'm not exactly sure on this car, but on my previous car I just couldn't get the hoses to seal up tightly so the vacuum leak code continued to come up, so I finally removed it.

@Pointbypatrol mentions removing his catch can for some reason or another in his most recent video.

Either way, the tuner should be able to sort it out.

Usually if it's after the pcv then it's just a fail safe to keep from blowing gunk out of the pcv and you shouldn't need to worry about leaks. The pcv then functions normally until blow by actually occurs, and for street use the can would likely stay entirely dry.

Most of the kits I've seen seem to delete the pcv entirely and then they're labeled as "non-carb and not for emissions controlled motors". I can see these causing issues since they're in full open vent or relying on a valve in the can.

Do you have a link to his vid? Know the spot where he talks about it?

 

[StingertimeNC]

link to vid:



early on I think. Not sure of the context, other than it was causing oil leaks.

In my case the thinking was just to cure the vacuum leak issue. May not fix the tune thing of course.

 

[jayy_swish]

Have a good scan tool?..or access to one? Try doing the idle relearn

 

[Two Step Performance]

I just have the hondata e85 base tune, you really think it’s the tune? I was driving with no issues until recently it started doing that when I installed intake, charge pipes, intercooler. That’s why I thought it was a vacuum pump, I’ll ask him hopefully he has some insight

I'd bet there is a leak somewhere in the intake system - could be at the intercooler, charge pipes, etc.

 

[SocalDE5]

I don't know much but it sounds like a fuel/air issue from your start up video.
Fuel pump... prob not
Maybe your flex fuel system... reflash the hondata map back onto your ecu.

Also.... everytime i mess with intake near the throttle body, i do a throttle body idle relearn.
That secret handshake with pedals and on off button sequence.

Sorry if i wasted your 27 seconds reading this.

 

[MacKharoni]

Clean your MaF sensor on your air intake

 

[wheresjc]

I just have the hondata e85 base tune, you really think it’s the tune? I was driving with no issues until recently it started doing that when I installed intake, charge pipes, intercooler. That’s why I thought it was a vacuum pump, I’ll ask him hopefully he has some insight

If thats when the issues started, thats where you need start looking. Pull the bumper back off and double check all the connections, and maybe intercooler o rings.

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