2013 Tahoe LS P0300 code

[Just00Jake]

I have a 2013 Tahoe LS that I've owned for about 8 months. When I bought this Tahoe it had a rough intermittent idle. I put a scanner on it, an inexpensive OBD2 and it said that the O2 sensor at bank 1 sensor 2 had a problem, so I changed it. Shortly there after I got a code that there was an issue with bank 2 sensor 2, I was getting a code saying it was reading lean in that bank and as I watched the live data, I was the voltages on it were only going high not low, so I changed it. Then immediately I started getting a code saying the heating element on my bank 1 sensor 1 was not working, but I so I replaced that O2 sensor. I don't know why I didn't change the last 1 yet but within days I started getting a misfire on cylinder #2. I tried swapping the plug wires around to make sure I didn't have a bad wire. **BTW I installed new plugs and wires a month ago, Delco Irridium plugs and Bosch wires. Immediately after swapping the #2 wire the code switched to a P0300 code. I had a mechanic scan the vehicle with a real scanner as I was advised to diagnose the exact problem instead of throwing parts at it until I figure it out and he said my #2 ignition coil was bad. I asked why it said "random misfire?" and he said " oh it will say that too" so I replaced all 8 of them. I reset the ECU and it ran fine for the rest of the day. The next day 40 minutes after starting it the check engine light came on and I started getting the P0300 code again. The misfire is obviously felt. I am waiting for the mechanic to get back to me to do another scan but I'm afraid if he guessed the first time this time will just be another guess. Does anyone have any advice? Also wanted to ask if the 2013 5.3l flex has an EGR valve? I've looked with no luck finding it but I'm looking for an old school EGR, and I don't know if the look different these days. I'm willing to fix the thing properly and with good parts but this is driving me nuts. Oh BTW I did check for vacuum leaks, cleaned my throttle body and my MAF sensor. I thank you for any help offered

 

[swathdiver]

Hi Jake,

For the money you've thrown at this already, you could have put a Tech-2 into your hands, the dealer level scan tool. That is past now. So exactly what kind of codes are you seeing currently?

Can your OBDII adapter see functions like misfires and fuel trims and such? Is this a little hand held unit or does it use an app on your phone?

 

[Just00Jake]

Hi Jake,

For the money you've thrown at this already, you could have put a Tech-2 into your hands, the dealer level scan tool. That is past now. So exactly what kind of codes are you seeing currently?

Can your OBDII adapter see functions like misfires and fuel trims and such? Is this a little hand held unit or does it use an app on your phone?

It is an app on my phone. I have just realized with the full paid version of this app that I can add items to my dash board and watch live data. I I'll check that out and get back to you. I have a "mechanic" bringing over his scanner tomorrow and will share that info. I would be willing to bet the educated advice will just be another guess. Thank you

 

[swathdiver]

If you are so inclined, sign up for a subscription to the shop manual at AllDataDIY. This way when you see the codes you can follow the trouble shooting guide for that code to solve the problem and move on to the next.

Note that a trouble code has a 2 digit symptom code right after it. These symptom codes tell you why the part failed, like 00 might be a short to ground, 01 might be an open circuit, 02 a loss of signal, etc.

 

[Just00Jake]

I apologize in advance if any of these pics are redundant. Keep in mind I only paid $20 for my little ODB2 scanner and the full app was only $10. Although it will tell you everything that my mechanic buddy's computer will. With the exception of the misfire count for each cylinder. BTW I had him tell me what the counts were trying to get a handle on if it's the #2 or a little of all of them since I get the P0300 or P0302 depending on how it feels. Cylinder #2 had 132 misfires and the closest next had 3. Let me know if you need to know anything else

 

[Just00Jake]

Let me know if anything else is needed. Thank you

 

[Just00Jake]

Also I wanted to mention that after reading way to much on this subject that I suggested to the mechanic the last time that I saw him that it could possibly be (1) a bad or going bad catalytic converter (2) a damaged or broken valve spring which isn't closing the valve so the way (exhaust or intake) which isn't giving me the compression to fire that plug or possibly the crank sensor. After he scanned it with his scanner he looked me straight in the eye and said it had to be 1 of 2 things... Either bad catalytic converter (which seems like it would effect more than the #2 since the each side is run by 1 cat. Or he said I could have a busted valve spring. I wish I would have thought of that. SMH. I did see the test done in a video. I think it's called a blow by test? You screw a thread adapter onto your spark plug threads once it is removed and after bringing that cylinder to TDC you shoot compressed air in at plug hole and if you have a broken spring then you will hear the air coming out of the exhaust pipe (if exhaust valve doesn't seal) or you will hear it coming out the throttle body butterfly. I have to figure out what the top is called. Thanks again for the help

 

[Just00Jake]

If you are so inclined, sign up for a subscription to the shop manual at AllDataDIY. This way when you see the codes you can follow the trouble shooting g anything that I thought might helpuide for that code to solve the problem and move on to the next.

Note that a trouble code has a 2 digit symptom code right after it. These symptom codes tell you why the part failed, like 00 might be a short to ground, 01 might be an open circuit, 02 a loss of signal, etc.

I am actually going to get the AlldataDIY. Thank you. I also posted any info that I thought might help. You mentioned the 2 digit"cause" code???? Do you see that code on my screen shots?

 

[donjetman]

The test you described is called a "leak down" test

 

[swathdiver]

I am actually going to get the AlldataDIY. Thank you. I also posted any info that I thought might help. You mentioned the 2 digit"cause" code???? Do you see that code on my screen shots?

I forgot and should have mentioned that not all codes have those 2 digit codes after them. I looked about your codes and they do not have a corresponding code after them.

When you get AllDataDIy, pull up the codes and follow the troubleshooting guide.