Blue_steel

So about a week ago I noticed while idling the rpms started dipping, i reloaded the tune and it didn't help. Well a few days later it throws a code p0442 evap system small leak detected, after this it seems to have gotten worse and now has begun stalling when I throw it in neutral at a stop. Any one have any ideas besides check the gas cap? Any help would be awesome as far as if these are separate problems or just one getting worse. And what to look for?

chub46

I got this from google search.

Evaporative Emission Control System Leak Detected (small leak)

What does that mean?

This indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

If I were you I would return it to stock and have the car checked.

Nuke

Before taking the car anywhere, I'd try cleaning the TB first. Even a mild build-up has been known to cause fluctuating idle and stalling problems. The CEL could simply be the PCM not knowing what's really going on due to the impact from the erratic idle.

And be sure the fuel cap is on tight.

Blue_steel

Update, I filled up and cleared the code and have not gotten it again since the day I originally posted this thread. I cleaned the throttle body but the stalling still happens randomly and if I sit idling for for than a few minutes the rpms dip and usually comes close to stalling or does stall more than once. I also can tell when it is going to do it because before when I come to a stop the idle starts to fly up to around 2500 rpms then the next stop starts doing it again.

Nuke

Fuel filter and a tank or 2 mixed with SeaFoam would be my next attempt. Be sure to run each tank mixture down as low as you comfortably feel but at least down to 1/4 tank. And be sure to do a few, good WOT runs to hopefully blow out some crud.

chub46

+1 on the fuel filter. How many miles do you have on that fuel filter?

Blue_steel

Fuel filter is only a few months old. I will try the seafoam and see how it goes.

Blue_steel

Finally got the issue resolved it ended up being the throttle pressure sensor. Hopefully this thread saves someone some trouble.

Nuke

That would be Throttle Position Sensor.

Glad you got it resolved.

Blue_steel

Yeah that thing lol.