Too much fuel?

'07 Spec.B

AP stage 2

ERZ catted down pipe

Apexi N1 cat back

 

I have lots of crackle and popping between shifts which leads me to believe things are way too rich. I also only get 20-22 mpg, on a really good week I might see 23 mpg.

 

I'll admit I am heavy on the thottle, but I drive 50 miles daily to work all highway and I set cruise at 70-75 mph. I also understand that winter weather will reduce my mileage. I guess I was looking for 24-25 at minimum.

 

I know I would be better off getting an infamous1 e-tune. But, would this also help my fuel mileage?

Do you have a BOV?

Other than the short list above everything else is stock power wise.

 

I forgot to mention my boost pressure is usualy around 17.5 psi but I have seen up to 19 psi. I tapped into the line at the bov which I know isn't the best place but............

I get 20 mixed on a custom stg 2 map. I think you're just being a bit too optimistic.

 

I get a lot of 'backfire' anytime I let off from WOT. Usually I get it the worst between 3500 and 4500 rpm. But I do sometimes get it at redline as well. If you get it ALL the time at redline, I'd say you should get a retune with a leaner map.

I guess I might be a bit naive with the MPG's. When I picked the car up 600 miles from home I managed 27 mpg the whole trip back. I would have to say for the power it has 22 mpg isn't bad.

 

I have honestly not been to red line yet. I purchased the car "stock" with 58,000 miles and don't know what kind of life it had before me. I have noticed hints of previous mods like SPT intake mounting studs and O2 sensor wires loose from the cut chassis mount zip tie things.

 

The AP st.2 map made a HUGE difference in the performance of the car. If an infamous1 tune will improve upon the AP tune I think I'm in for a new tune. I just read through the whole "Who else loves their infamous1 tune?" thread and only found 1-2 comments about switching from COBB AP to infamous1 tunes. Is there anyone else with this experience?

My advice would be this: grab a couple more mods before getting retuned. For example, I just went FMIC and am planning to get an intake to compliment the mod. After these mods, my stg2 map won't really be of much value for me, hence the retune. Going from Cobb AP Stg 2 to Infamous Stg 2 may very well be a big step, but I'd encourage you to make some changes to really 'need' a tune before going all out. Either way, best of luck.

I'll take your advice and run with it. I was leaning in this direction anyway. There are a ton more things I would like to do.

 

Thanks everyone for your input, you saved me $150 for now.

I'm getting ready to switch from my AP OTS tune to an infamous tune later this week after my new intercooler arrives. If you already have an AP, you might as well keep it until your mods exceed what the OTS map can handle.

 

As far as running rich, I just found out mine was running really rich because of a boost leak from a leaking endtank. A quick way to check for a boost leak (courtesy of lgtftw) is to disconnect the tube from the airbox to the engine and blow into it while listening for leaks.

I have noticed a funny whining sound at higher boost levels. I may have to try this test of yours.

 

Thanks