Ok so i got a question and im pretty sure i know the answer but i want to make sure. I have a 07 ss/sc and i have stage 2, the rest of the mods r in my sig. My tune wasnt set up to its full potention cuz i got called away with the army and wasnt able to get it finished. So at 4000rpm it drops abit rich and then comes back up. So now u know the deal with my car.

So i have a injen cold air intake and i have never changed the filter, it has 49,000km on it and i washed it but it didnt clean really well so i bought a new filter which will be here sometime next week. Now this weekend im planning on going to my mechanics shop to finish the tune. My question is since the filter that is on now is so dirty...if i tune with that and then change to a brand new filter will it mess up the a/f ratio? I'm pretty sure it wont but for some reason i have a feeling it will cuz if the tune is adjusted to the air flow that the car is giving now and then all of a sudden switch filters which will flow abit better it might mess something up.

 

no..

 

umm ok. Reason why im asking is cuz i went to a local shop and bought a filter, it wasnt injen but it was the same size and the guy said it would work. tried it, it fucked my tune up bad, a/f was all over the place. Changed it, tune went back to normal. So obviously the intake does play a role in the a/f ratio

 

^ are you changing the intake? or just the filter? a filter shouldnt change anything

 

im changing the filter since the one that is on now has about 50,000km on it. I figured it wouldnt do anything but someone asked me that and i wasnt sure and it got me thinking. Like i said before. I bought a filter but not a injen one, same size tho. And the guy at the shop told me it would work. When i put it on the a/f went ape ****....checked to see if it was tight enough, everything was fine but the a/f just went to hell...would not stay stead, kept going to rich and to lean at WOT and normal driving.

 

During normal driving its normal to have the aem wideband's be all over the place. Basically from 13-15 is what they can read, generally there not 100% steady at 14.7 or they are only for a few short seconds. Have you tried cleaning your maf? If you used a different filter with oil on it, you could have gotten oil on the maf. This is pretty common with k&n filters that use oil. I recommend cleaning the maf and installing your new injen filter and going from there. Also it will NOT mess up your tune to tune your car with a dirty air filter and then replacing it with a new air filter. It won't change a single thing. The small increase in air flow won't even be noticed and the maf will compensate for it. Your air to fuel ratio will be determined by your tuning more then anything.

As far as the random no name filter you bought messing with your air flow it could be several things. Either a leak somewhere, a different material/filter type allowing A LOT more air through etc, however these things would generally pop up a code instead of messing with your air to fuel ratio OR it could be a placebo effect aka you think somethings wrong so there is lol.

But like I said as long as you aren't in like the 10's, 11's, 12's while regularly driving then I doubt theres a big issue. Either way I would still recommend putting back on the correct injen air filter and cleaning the maf. But to answer your question in short, no a dirty air filter will not effect your a/f ratio during tuning.

 

thanks, yea when i had that other filter own it would go from 11 - 16 on the wideband and i could feel the engine giving abit of a shake. But ill do that once my filter comes in next week with the maf sensor.