P0300 Code
 

My truck an 05 Silverado with a 6.0 Engine seems to run good.
My check engine light comes on giving me a P0300.

The following is the freeze frame data:
DTCFRZF P0300
Fuel sys 1 CL
Fuel sys 2 CL
Load % 43.5
ECT F 377
SHRTFT1% -0.8
Longft1% 6.3
SHRTFT2% -0.8
LongFT2%4.7
Map KPA 50.0
RPM 2488
VSS 65 MPH
Spark advance 33.5
IAT 48 out door was 40
MAF g/s 54.23
TP% 29.4

The ECT of 377 jumped out at me so I went out to the truck to see what the temperature guage read it was around 210 I connected the scanner to live data and the ECT read 201 F but the IAT read 91F when it was 40F

I guess I'll be checking out these 2 sensors
Any advice would be appreciated

Rick

Re: P0300 Code
 

Most people don’t believe that a bad coolant sensor can cause a misfire. However, the computer that sees a “really hot temp” will compensate for what it thinks is a lean condition. I would bet that you have a faulty ECT sensor. Let us know if that’s the case.

Re: P0300 Code
 

Thanks for your reply Evrlet

I cleared the code, drove home as I did yesterday with the scan tool on live data and I attempted to make the code come back by driving and a hard acceleration like last night the SES light flashed but did not stay on so no code.

I did start fooling with the connector but it got too late for work and I had no time.

I was monitoring the ECT and it got no higher than 202 degrees F

Re: P0300 Code
 

Is there a problem with the connector, corrosion, or damage to the wiring to the ECT sensor?

Try Deoxit D5 on the connector and sensor pins then plug/unplug it several times???

Re: P0300 Code
 

Thanks I'll try that

Re: P0300 Code
 

It's not impossible to have the sensor flaking out intermittently too... I usually don't shotgun stuff but... They're cheap.

Re: P0300 Code
 

I had a P0300 I chased on my LQ9 swapped Z28 for a year. Finally found it with a noid light set. Ended up being a fuel injector plug that had 1 strand of copper left connecting it.

I agree a faulty sensor could be the culprit. Grounds are a huge player in the LS engines as well, make sure they are all clean. Next place I would look into was plugs/wires.