Hi guys,

I hope you can help me understand this data I recorded after a pulsing idle and p0300 code.

ECT 186 degrees
STFT -2 to +3
LTFT 0 steady
STFT -1 to +3
LTFT 1.5 steady
RPM -+800
Spark Adv 12
IAT 87 degrees
MAF 1.3
TPS 19.2 at idle 30.0 slight accel
O2S B1 S1 (v) .075 to .775
STFT B1 S1 (%) -1.5 to +1.5
O2S B1 S2 (v) .890 steady
STFT B1 S2 (%) NA this is concerning
O2S B2 S1 (v) .090 to .775
STFT B2 S1 (%) -2.3 to 1.5


Like I said, It pulses at idle and shudders. I'm concerned with the 'NA' on STFT B1 S2. Can someone explain the data or direct me to a resource?

Thanks!

Diamond-X

 

Anyone? I replaced the plugs, boots and fuel filter. O2 Sensors are next.

 

I havent inspected this system so my best guess is there isnt a sensor in the location where u have "na". Most cheaper scanner dont load car/truck specific data info all the time so they show "na" in these locations. If u were to look at monitors and say ur truck doesnt have a "egr" it would say "na" next to the "egr" monitor. Totally normal.
P0300 is random misfires. I would inspect the boots,coils,plugs

 

Anyone?

10char

 

P0300 is a random misfire. Something that would effect all cylinders like EGR, vacuum leak, fuel pressure.

 

Did you replace the plugs, boots, fuel filter, etc prior to the problem or as a responce to the problem?

Your Short term and Long term fuel trims look pretty good so I wouldn't suspect an 02 sensor problem unless your not seeing voltage coming off one of them...

You might want to look at your MAF sensor. Does the voltage seem to swing on that at idle?

 

Have u checked for water in the fuel. Easy to do.
Did u get fuel recently?

 

I replaced the plugs, boots and fuel filter in response to this problem. It runs stronger above idle but shudders at idle especially when cold. MAF seemed to be fine, stable at idle and climbing under slight accel.

With the Excursion I get fuel once a week. I did put a bottle of fuel treatment in and 50 miles later a bottle of injector cleaner.

The O2's are original with 181,000. I think I'll change 'em.

 

Did you try cleaning the IAC?

 

Get a good OBD Scan tool that will read Mode $6 data. You should be able to pull up the misfire counters for each cylinder (if Ford has the feature on the Ex).

 

EGR was sticking open, causing the stumble at idle. Replaced and running perfect now!

 

Good job.

 

You called it Shepherd2!

 

Unless I put slight input into the throttle, looks like the IAC. Just ordered from rock auto, $58 delivered. I'll post the results of the swap.