So, I've noticed that when I get on it, about after 6500 rpms the car makes like a "putt, putt, putt, putt" noise and kind stops accelerating before it backfires and then picks back up. Its only started doing this for the last 2 days and it isn't a all the time thing, its like maybe 3/4 of the time.

Anything I should look at, be concerned about?

 

Any codes?

 

I would check your spark plugs first since thats pretty easy, it does sound ignition related.

 

I haven't had it checked for codes.

I don't know much about the car, bought it used from a dealership.
It was fully built 3 years ago and tuned on a AEM standalone with E85

When I bought it, I had it retuned by the same shop on that tuned it 3 years ago on pump gas.

I'll definitely check the plugs though.

 

Cool, checked the plugs and replaced them. Definitely feels better, less sluggish, but still does the "putt, putt, putt" not as bad as before though.
I called the shop that did my tune and they also suggested having a bad injector.
Does that sound like the next logical step?

 

Did you replace the plugs yourself? If so, did you gap them correctly? Running on E85 requires slightly different gaps versus pump. Having a bad injector may be possible; however, running on E85 is actually better for injectors--less chance for them to get boogered up.

 

Yeah I replaced them myself. The shop told me to gap them down to 25 so that's what I did, and it's no longer running on E85 it's on 93 now.

 

Stock air box?

 

I had similar problems over the weekend it turned out to be very loose LICP. I had a very loose coupler...Backfired and got rich. Check your LICP, vacuum hoses from J-pipe, UICP hoses, and every vacuum lines. This should be a monthly routine for everybody.

 

Are you running a wideband? what are the mixtures like? When I had an issue like this boost was outing the spark had to regap my plugs even closer...

 

Its got a maf delete. I'm not running any filter or intake

 

Yeah. When I got it tuned they set to run in the 13s to avoid going to lean.

 

id do a boost leak test, and check all your injector clips, make sure one isn't loose or the wires are half pulled out of the clip

 

wouldn't think it would be the infamous p0300 on an 05

 

[QUOTE=son of krypton;10845734]Did you replace the plugs yourself? If so, did you gap them correctly? Running on E85 requires slightly different gaps versus pump. Having a bad injector may be possible; however, running on E85 is actually better for injectors--less chance for them to get boogered up.[/QUOTE


No its not e85 clogs the injectors thats why after so
Many miles you have to run 93 octane or a strong ethanol treatment to clean the injectors again.