[Stale_Hotdog]

Hi i've been getting this code every couple tanks of gas recently. I have an 08 s240 engine mods on the car are (Cup car airbox, larini clubsport 8 inch exhaust, zeitronix a/f ratio sensor and display, sikou michi catchcans, and gotham tune.) I attributed it to bad gas but I've tried different stations and it's been popping up like clock work. Anything I should check for?

 

[Thomasio]

Is this the first time you have driven it after storing for winter? (Condensation).

Also check your plugs... water collection inside the plug tubes will cause a misfire.

 

[Stale_Hotdog]

It is my daily driver. I am located in California so I have never stored it or not driven it for more than 2-3 days. It is garaged nightly as well.

 

[apk919]

You mean P0171, right?

Do you have an OBD-II scanner with real time data display? Check your fuel trims (STFT, LTFT) to see if they're near the limit of +17%...

 

[Stale_Hotdog]

I have an OBD-II scanner not sure if it has real time display though

 

[apk919]

I have an OBD-II scanner not sure if it has real time display though

If it doesn't see if you can borrow one that can. Two important parameters are the Long Term Fuel Trim, and the Short Term Fuel Trim... basically it's telling you how much above or below the baseline tune the ECU is setting the fuel mixture. If the fuel trim goes above 17% (it's adding fuel, since it senses a lean condition), it usually indicates that the ECU is having trouble getting the mixture right...

What does you AFR gauge say, BTW?

CharlieX would probably have a lot more to say on this issue...

 

[charliex]

"larini clubsport 8 inch exhaust"

that'd be my first guess.

 

[Stale_Hotdog]

I was worried you'd say that . My af gauge flucatates a little at idle it bounces around 14.5-14.7

 

[charliex]

for idle thats fairly normal, its trying its best to maintain 14.6

 

[Chili Red]

"larini clubsport 8 inch exhaust"

that'd be my first guess.

Id say cup car air box is the issue. I put it on a few months ago and I'm getting the same code...

 

[charliex]

its possible, but just do a search on larini p0171 (or lean), and i'm talking about results we've seen on the dyno too.

 

[shay2nak]

I'd say cup box also.

There are ODB readers that will tell you fuel trims?? I bought one but it was cheap, $70. Don't think it does it. Maybe I can exchange...

 

[charliex]

i'd be shocked if it didn't, not at $70. look for short term and long term fuel trims,or STFT LTFT

 

[apk919]

I'd say cup box also.

There are ODB readers that will tell you fuel trims?? I bought one but it was cheap, $70. Don't think it does it. Maybe I can exchange...

To see fuel trims you have to get a reader that displays real time OBD-II parameters... they're a little more expensive than the ones that just read and reset DTCs (CELs). There are quite a few standard fuel/emissions related parameters (since emissions was really the point of the OBD-II standard... you can thank CARB for that)

 

[mrcarcrazy]

Thread revival. I've gotten this CEL twice so far. just over a month and 1000 miles between the two incidents. I do not have an aftermarket intake. and no recent mods to the car.

My Reader shows a snapshot of what was going off when the CEL was set.

so here's that
Load PCT 33.7%
ETC (F) 172
Shrt FT 5.5
Long FT 8.6
Rpm 1650
VSS 2mph
MAF 1.041
TP 14.9%

Any ideas?

 

[alexscotti]

Check for exhaust leak

 

[spectre]

I had that same code and cup airbox. Went back to stock Airbox and have not had it come back. I do have the clubsport exhaust.

 

[mrcarcrazy]

ok, I'll check for exhaust leaks, anything else I can look for/ test while I'm under the Car?


Again stock intake. and no mods in the past year except STS. This code has popped up twice in the year I've owned it. almost 1000 miles separate the two incidents.

 

[Simba]

Probably an exhaust leak. If you're running the stock engine mounts, check your manifold studs/bolts and make sure they're tight. In my experience it's quite common for the manifold to work loose due to the stock mounts allowing the engine to move around A LOT.

 

[mrcarcrazy]

Probably an exhaust leak. If you're running the stock engine mounts, check your manifold studs/bolts and make sure they're tight. In my experience it's quite common for the manifold to work loose due to the stock mounts allowing the engine to move around A LOT.

Interesting. will do.

Thanks guys.