Hello again. I own a 2019 Hyundai Elantra GT N - Line. Got around 12,600kms on it - with full bolt-ons and a chiptune. It's been running perfectly, no problems at all. I always use full synthetic oil and I always change it very early, every 3,000/4,000kms because of my driving habits. And because of that, I decided to get the intake/fuel system cleaned using the factory CRC product.
All that went well, apart from the intake/fuel system cleaning. That's when it went all downhill. Hour before, the car ran perfectly - it can do extremely high speeds very quickly, full bolt-ons and a chiptune with this car equates to around 300hp or more. Now it barely does 120 on the highway with my foot to the floor.
Full story, pulling out of the shop, immediately the car has a huge loss of power - stuttering, running extremely rough - turbo was surging, barely making ~6psi (before 26+) of boost. CEL flashing for a few seconds, then went away (Codes were P0300 to P0303 Random cylinder misfire).
Thought that was fine, since every other time I did it, the car needs to be driven at high speeds for a little bit to clear all the junk out - it's what I always do.
Then 50kms later, the situation improved a little but the Catalyst was getting extremely warm by this point, 1879f, engine temp was fine - its winter so I have the heater cranked already and the car was running noticeably rich even 6 highway loops later.
It's idling at around 1100-1200RPMs, and it's very rough and shaky. Beforehand, it idles at around 600 to 650RPMs, and it does so extremely smoothly, you can barely even notice it was even running. By the time I got home, my once full tank was down to about 3/4s of a tank. It used a good 25% of fuel from 6 loops and ~40 to 50kms. And it was still idling and running so badly that I have to floor it or else it'll stall at a dead stop.
I have a feeling whatever product they used on my car, fouled all four sparkplugs badly...and help? Thank you.
Did they spray that intake valve cleaner directly into intake BEFORE the turbo or straight into the throttle body? I have used that CRC product before, and it did cause some hiccups on my engine too (but with noticeable results after). It didn't cause any misfire codes, but it did throw a rich code along with limp mode. However, it definitely felt like the engine was misfiring. It took about 3 days for it to fully clear out of the system. I sprayed the cleaner BEFORE the turbo, and I believe a majority of the product got stuck in my intercooler, hence why it took a while before it fully cleared out. I don't think your plugs are fouled. I checked mine when I had the issues, and they were in good shape.
Also, if they did spray before the throttle body, I would clean the MAP sensors as those are definitely covered with the product and probably giving the ECU bad data.
Maybe just drive the car around for a couple of days and see what happens. Don't drive it too hard though lol.
Good luck! Us FBO guys go crazy when something goes wrong with our cars lol.
I do have a CAI on the car and it doesn't have any vac lines on it so they had to use some kind of hose, after the turbo going into the throttle body.
@flukey
Well having a CAI or not doesn't change the fact whether they sprayed into the piping before the turbo or into the throttle body. They could've taken off the MAF sensor (before the turbo) and sprayed it through there. Have you told the mechanic about this? Clearly they didn't follow the directions, because if they did they would've taken the car for a 45 minute drive as per the instructions and would've noticed the misfiring. Well I hope it naturally clears out and not a bigger issue. Trust me, I learned my lesson from this spray too lol.
Wasn't able to edit the reply above but, I kinda had to drive it 'hard' i guess since it had zero power....idling around 1200rpms, running very rough, and if I were to drive off normally - it would stall instantly.
I had no low-end power at all, barely making it to 100km/h let alone 120.
And I took it to an oil change shop, Hyundai was closed - went to Mr. Lube, local service in Ottawa. never had a problem with them before from the span of the 5 to 10 years.
@flukey
So you think the oil change caused this problem? Was this done at the oil change shop?
Nah, definitely the CRC product. The MAP sensor was greasy, and the inside of the intake manifold was still rather wet from the product. They used the PCV hose on the throttle body for the product.
After I cleaned the sensor, its not misfiring or idling high anymore. Will give it a drive.