2G Running lean

[rydereclipse]

This has me stumped...please try to help.

Here's what's going on...

When the car is first started, it starts at 14.7 and cycles up and down for about 10 seconds then starts dropping to 17+ and pretty much stays there.

I have tried - checking for boost leaks, found a couple minor ones...didn't help.
- changing the wide band O2 sensor, didn't do anything
- recently changed the front O2 sensor...checked Evoscan and it is cycling
- checked the CTS it working and sending the right signals
- checked the injectors and unplugged them one by one, each made a noticeable difference when unplugged, so I assume they are working
- my fuel pump has only 600 miles on it since new, and it can hear it working, it is also rewired, so it's getting plenty of power
- checked my FPR vac hose and there is no gas in the line ..I assume if the FPR took a crap I would run rich
- 200 miles on a brand new fuel filter and new filter to rail line..it's not kinked...
- checked for exhaust leaks pre-wide band found none

This all started happening over the weekend, my CAS plug came loose and I babied it home, plugged it back in and it was fine. But it seemed like that is when the problem appeared.

It does sound like I have a vacuum leak but I can't find any, checked throttle body gaskets and plugs with soapy water..got nothing..

I do not have a AFPR..It's next on the list...

Any ideas on things to look at...

 

[Soccerguy136]

If it happened over the weekend and you babied it home with the CTS unplugged, the ECU probably needs a reset or to re-learn what's going on with the CTS plugged back in.

Is it only happening during idle?

If it is, then just drive normally and allow the ECU to enter "learn mode" and reset itself. Or you could try unplugging it and plugging it back in.

Make sure to watch your WB the entire time and don't boost too hard until you are sure it is not leaning out.

 

[Mirad]

Try this since you suspect a vacuum leak.

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[leathaleagle21]

That smoke trick is a good idea.

 

[Soccerguy136]

Only someone with a Mustang could have figured that trick out .

But I agree, that is a brilliant idea.

 

[4Gwannabe]

How's the plugs look? Could be fouled buddy happen to me same symptoms

 

[952g63t]

This has me stumped...please try to help.

Here's what's going on...

When the car is first started, it starts at 14.7 and cycles up and down for about 10 seconds then starts dropping to 17+ and pretty much stays there.

I have tried - checking for boost leaks, found a couple minor ones...didn't help.
- changing the wide band O2 sensor, didn't do anything
- recently changed the front O2 sensor...checked Evoscan and it is cycling
- checked the CTS it working and sending the right signals
- checked the injectors and unplugged them one by one, each made a noticeable difference when unplugged, so I assume they are working
- my fuel pump has only 600 miles on it since new, and it can hear it working, it is also rewired, so it's getting plenty of power
- checked my FPR vac hose and there is no gas in the line ..I assume if the FPR took a crap I would run rich
- 200 miles on a brand new fuel filter and new filter to rail line..it's not kinked...
- checked for exhaust leaks pre-wide band found none

This all started happening over the weekend, my CAS plug came loose and I babied it home, plugged it back in and it was fine. But it seemed like that is when the problem appeared.

It does sound like I have a vacuum leak but I can't find any, checked throttle body gaskets and plugs with soapy water..got nothing..

I do not have a AFPR..It's next on the list...

Any ideas on things to look at...

Did you solve your lean issue?