Mods:
Stillen Gen 3
ART Pipes
Top Speed Y back
So I installed my ART Pipes and Top Speed y back about a month ago and no CEL came on until two days ago. I thought the cat code was popping up but went to oreilleys and the only code stated the engine was running lean. Can I damage my engine with my mods and no tune I'm planning on tuning when I save up but need to know so I can prioritize it before I damage anything.

Any input?

 

Here's the code

 

I would first check for a leak in your intake. You should also clean the maf sensor.

 

Yes you can damage your engine. Won't happen at cruise or light throttle but you can injure the engine at WOT. Do you have an OBD bluetooth reader? You can use a program like Fusion to actually record and monitor your a/f ratio.

The Stillen works by tricking the MAF sensor and leans out the motor. I have an intake, high flow cats and the stock IPL dual exhaust and I'm actually rich. Really rich in fact.

I'd suggest either removing one mod or not going to wide open throttle until you can get a tune.

 

Thank you I will make it a priority then. It's the ART Pipes because my Stillen Gen 3 was put on for months without a check engine light

 

I'm actually going to get the car checked it can also mean a exhaust leak maybe?

 

Running lean usually means more air going into the intake. I just read that it could happen from a leaking exhaust. Who knew.

 

Yeah I'm going to get everything checked this week. I want to take it to the dealer but I'm worried if they blame the mods I have infiniti elite warranty. I'm going to call them and ask them to see if they can at least check it out

 

Since the lean code is just on bank 1 (passenger side) check the intake parts for proper alignment and proper clamping. Also check the PCV system for leaks, as it can introduce air AFTER the MAF.


One case I saw recently, there was a very small crack in the factory header. When the exhaust has a slight negative pressure, this allowed oxygen into the exhaust, which the A/F sensor reported as "too lean"

 

Dang, I have all the bolt-ons without a tune and haven't seen a CEL yet, knock on wood..

 

Just curious, what is your AFR at WOT?

 

I doubt it's the mods I'm getting to a consensus that I got several professional opinions and mostly everyone is indicating that's it's not cause by the mods. I hope so I'll update this on Saturday after I get my car checked

 

Low 10's to very high 9's at redline.

 

My bone stock G37 has similar AFR when the ambient temps are high. The rich mixture is used to cool the combustion chamber to prevent detonation.

On a cool day they are mid 12s at WOT.

 

I did not know that! I'll have to check my a/f tomorrow. I did verify the readings on a dyno with their wideband and it had the same readings as my bluetooth OBD dongle through Fusion. I can't get my sample rate as high as I'd like (about four samples a second). But I can still see the trend and interpolate.

I'm in Texas and if I remember correctly, I was taking readings mid-Summer. I'd also usually do it first thing in the morning however. Ambient temps were usually in the 80's.

Edit: Just checked, yep my logs were in July so it was probably in the high 80's by 9am and into the 100's later in the day.