Post-Shark Injector Install Stumble/Rough Idle

[04TitanSilber]

Hey guys, long time lurker here, I think only second time poster. Love the forums and community here. I just installed the Shark Injector last night. I followed the instructions to a "T" and the install went perfectly. I took the car for a spin and everything was running great, except I noticed the idle was rougher than before the install. The car idled perfectly before (just cleaned the ICV a couple thousand miles ago). Now, it seems like the car wants to idle too low, creating king of a lugging sound. I've also noticed the car "hunting" for the right idle speed after letting off the throttle more than it did before, although not every time. Throttle response is great- the car comes off idle without any hesitation and pulls strong to the new redline. It's only at idle that I'm feeling/hearing the roughness.

I searched around a bit and didn't see anyone complaining about the same thing. I'm thinking it could just be the car "relearning" everything after having the adaptation values cleared by the reflash- maybe it will go away after a few days? Any thoughts?

Car is an 04 6 speed with 82k miles and a K&N intake. I would emphasize that it was running absolutely perfectly before the Shark Injector install and all maintenance is religiously up to date.

Thanks guys.

[ZHPizza]

That is pretty weird. Are you sure that you got the right shark injector software? I'd reach out to Turner via chat -- they're always responsive.

[04TitanSilber]

Update: car threw two codes driving home from work today:

2882 mixture preparation bank 1
2883 mixture preparation bank 2

Rough idle is still there as well. I searched around and it looks like this may be a common issue with the Shark Injector. I can say with 100% certainty there are no vacuum leaks, DISA is new, ICV is clean, etc. Car was running perfectly before Shark Injector install. Turner will definitely be hearing from me tomorrow.

[Reasoned1]

What octane gas are you running?

I've read everything I could find about the Shark Injector, and I'm unfamiliar with any "common" issues. I have it on three cars (two with K&N intakes) without any problems (other than my own mistakes).

Not saying it's not that, but I'd be surprised. Of course, you can restore your factory software to confirm the Shark is making the difference.

[coby1]

would say un-install shark see if issues remain

[ELCID86]

Agree with Mike^. Could be a coincidence? :dunno

[Aeternalis]

would say un-install shark see if issues remain
+1 definitely. Unshark and see if issues remain.

[04TitanSilber]

Thanks for the input, everyone! I'm almost ready to admit I was wrong about the problem being Shark Injector-related, but not quite :). I unsharked the car and the problem persisted. I kept researching and it sounds like the "mixture preparation" codes often result from a lean condition. Since it threw the codes for both banks, I figured maybe there's a vacuum leak between the air filter and throttle body. Again, it seemed highly unlikely that the car would have coincidentally developed a vacuum leak literally the first time I drove it post-Shark install, especially since I just replaced the lower intake boot, but hey, anything is possible.

I checked for a vacuum leak the old school way my dad taught me - spraying some brake cleaner (less flammable than other stuff) around the intake and throttle body and seeing if the idle jumped up. I'm open to other safer suggestions if anyone has any. After spraying in a few places, the idle seemed to jump up when I sprayed right onto the lower intake boot where it connects to the throttle body. I figured maybe I didn't tighten the hose clamp enough when I replaced the lower intake boot. Or, maybe the boot pulled off the throttle body a bit after a few high-rpm pulls to test out the new Shark Injector? I seem to remember I couldn't get a socket in there the first time around and just tightened the hose clamp with a screwdriver. This time I was able to get in there with a socket and tighten it up (it was kind of loose). After that, I sprayed around again and no changes to the idle!

Feeling confident I had the problem solved, I went for a drive and the car was still doing the same thing - bogging and almost dying when returning to idle - although not 100% of the time. Then I came home and cleaned the MAF, although it looked spotless to begin with. I started the car and it still did the same thing. But, this morning I drove to work (25 min drive) and the car ran totally fine. It also hasn't thrown a code since I cleared the codes around 30-40 miles ago.

I guess I'll see if anything else develops in the next few days, but I'm kind of at a loss. Maybe the ICV is bad? I just cleaned it, but maybe the whole thing needs to be replaced. But then I don't see how that would throw a lean code, especially since the light came on when I was cruising at around 2500 rpm...

[Dave1027]

I checked for a vacuum leak the old school way my dad taught me - spraying some brake cleaner (less flammable than other stuff) around the intake and throttle body and seeing if the idle jumped up. I'm open to other safer suggestions if anyone has any.

Google "smoke test".