Intermittent rough engine and misfires both in idle and while driving, codes P0305 and P0300

Tiny
NYC2NC82@GMAIL.COM
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I circled where those 4-550 temperatures were coming from. Temperatures all around and below that area was normal. That elbow further up the circled area in the picture is where it looked like the smoke was coming from
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Monday, July 27th, 2020 AT 10:47 PM
Tiny
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Hmm, very interesting. Can you see where it's coming from and going to?
Tom
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Monday, July 27th, 2020 AT 11:50 PM
Tiny
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It comes from this part here in the pic. I think this is the vapor canister purge solenoid from what I was able to see online. I apologize if I m wrong. It located in this Jeep up front by the battery and there s a couple of tubes running from it, including the one getting the high temps. It looks like it runs to the elbow and into the firewall (attached pic) not sure where it goes from there. I checked temperature through the rest of this line from start to finish and those 4-500 temperatures only came from that one section.
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Tuesday, July 28th, 2020 AT 3:36 AM
Tiny
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From what I ve found, the EGR is also on this same side. Supposed to be on the back of the left cylinder head.
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Tuesday, July 28th, 2020 AT 10:47 AM
Tiny
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Is that the fuse box I see its attached to and the tubes are running by? In the first pic.
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Thursday, July 30th, 2020 AT 7:01 PM
Tiny
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Yes. It just slides on and off. And thinking about it, I remember that part just laying on its side and I put it back on there.
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Thursday, July 30th, 2020 AT 7:08 PM
Tiny
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Okay, so if its the tube that getting super hot then EGR has failed. Its a mechanical and electrical unit and when it starts to fail the gate sticks either open or closed. When this happens the car will start to through the codes that your seeing and run rough. That's the part in the picture. I think that's going to take care of the problem.
Tom
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Thursday, July 30th, 2020 AT 8:39 PM
Tiny
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Everything I m pulling up, that s the purge valve pictured not the EGR. The EGR is supposed to be on the rear of the left cylinder head.
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Thursday, July 30th, 2020 AT 8:52 PM
Tiny
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Would that cause the same issues? And would either throw injector codes?
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Thursday, July 30th, 2020 AT 8:53 PM
Tiny
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The unit connected to the hot tube I believe is going to be the issue. I too will double check that part and the one your speaking of at the other location. I may be mistaken on its name. Can you make out the part number on it somewhere?
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Thursday, July 30th, 2020 AT 9:03 PM
Tiny
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EVAP canister purge solenoid is what I m finding for that part.
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Thursday, July 30th, 2020 AT 9:15 PM
Tiny
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And this is what I m finding as far as where the EGR is. It is in the general vicinity where smoke was coming from, just not sure if it was from there or not.
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Thursday, July 30th, 2020 AT 9:18 PM
Tiny
4DRTOM
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Good morning,

You are correct the picture is showing a purge valve and when it goes bad it throws a code for it most of the time. It's not the codes you are getting and its symptoms are not what you have, It's recirculating fuel vapor from the tank to the intake to burn off the fumes, it's an emission control component. The EGR failing has all the issues you are having both the running aspect and the code aspect. It sticking can explain the slight smoke you are getting as well. The EGR can be bad and not send a code for it too. Something is very odd having the tube from the purge valve being so hot and it has fuel vapor and plastic? The EGR is a recirculating operation which might be creating the other part to heat up. I suggest doing the EGR.
Tom
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Friday, July 31st, 2020 AT 8:32 AM
Tiny
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Morning. I will look into it, luckily the EGR is not expensive. Would the EGR be something that gets worse with more heat? As far as that tube, I m only getting those temperature reading in that one section, nowhere else on that tube.
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Friday, July 31st, 2020 AT 8:40 AM
Tiny
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Good morning,

Yes it would get worse as the temperature increases like you have going on. It's very interesting that a plastic tube would read those numbers and it hasn't melted down.
Let us know how it works,
Tom
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Sunday, August 2nd, 2020 AT 8:00 AM
Tiny
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I find it interesting about the tube. Not sure if it s a bad reading but I checked all around and even pointed the beam all over the place underneath it to see if it s another part and it only went that high when the beam was directly on the tube in that one section.
Would the EGR cause the injector codes? Not doubting you at all, I know the EGR can cause misfires just trying to understand how that fits with the injector codes. Currently have p202 and p204 as well as p307.
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Sunday, August 2nd, 2020 AT 8:50 AM
Tiny
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Hi,

Seeing that the EGR is both an electrical and a mechanical unit on those vehicles, then yes. The electrical part is connected to the computer and if the computer is getting bad information strange things can happen. With having injectors codes with new injectors installed rules out the injectors especially with knowing that the engine isn't getting hot. We can also rule out a bad ground or bad wire/harness to the injectors because you running okay at cooler temperatures.

Has the p0202 and p0204 been coming and going, and the p0300 and p0305 gone leaving p0307? When you are pulling the codes has it been while the car is still hot and running bad or are these codes pulled when its cooler with the codes stored? What is the laser point temp at the EGR tubes coming from it when it's running badly? With all this we have gone through to get to where we are puts the ECU itself in question. That not being a cheap part, we need to know for sure first. Radiant heat warming up an ECU that's borderline beginning to fail could cause misguided codes. If its possible maybe try to out a piece of foam or sheet metal around or between the ECU and motor to insulate any radiate heat getting to it and see if there is a change in the time the engine starts to run badly. It's just a thought.
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Sunday, August 2nd, 2020 AT 2:14 PM
Tiny
4DRTOM
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I believe some of this has been done but here is what they give us for an intermittent conditions its worth reviewing.

Diagnostic Test
1. INTERMITTENT CONDITION

NOTE: The conditions that set the DTC are not present at this time. The following list may help in identifying the intermittent condition.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

Refer to any Technical Service Bulletins (TSBs) that may apply.

Review the scan tool Freeze Frame information. If possible, try to duplicate the conditions under which the DTC set.

With the engine running at normal operating temperature, monitor the scan tool parameters related to the DTC while wiggling the wire harness. Look for parameter values to change and/or a DTC to set.

Turn the ignition off.

Visually inspect the related wire harness. Disconnect all the related harness connectors. Look for any chafed, pierced, pinched, partially broken wires and broken, bent, pushed out, or corroded terminals.

Perform a voltage drop test on the related circuits between the suspected inoperative component and the PCM.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Inspect and clean all PCM, engine, and chassis grounds that are related to the most current DTC.

If numerous trouble codes were set, use a wire schematic and look for any common ground or supply circuits.

For any Relay DTCs, actuate the Relay with the scan tool and wiggle the related wire harness to try to interrupt the actuation.

For intermittent Evaporative Emission trouble codes perform a visual and physical inspection of the related parts including hoses and the Fuel Filler cap.

For intermittent Misfire DTCs check for restrictions in the Intake and Exhaust system, proper installation of Sensors, vacuum leaks, and binding components that are run by the accessory drive belt.

Use the scan tool to perform a System Test if one applies to failing component.

A co-pilot, data recorder, and/or lab scope should be used to help diagnose intermittent conditions.
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Sunday, August 2nd, 2020 AT 2:17 PM
Tiny
NYC2NC82@GMAIL.COM
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Before I start I do want to say thank you both, this has been a pain and hoping that get it right.
As for the codes, before the injectors were replaced I would say the issue was more frequent and it did not need to be as hot out for it to get pretty rough. After the changing them I ve had some days where it s not quite as hot out and have near perfect driving.
Before the injectors the main 2 CEL codes coming up were p300 and p305. I had p207 one time before I did the alternator and it never came back.
Currently after the injectors I have p204, p300 pretty consistent. Have seen them both stored and pending at same time. P307 started coming up approx a week later same as those(stored and pending). And yesterday driving on highway to swap cars with my buddy I had some pretty rough driving and the CEL even started flashing on me 3 separate times for a few seconds and stopping. When I got stopped is when I saw p202 was also pulled. So currently I have on the cel p204, p202, p305 and p307. Codes on both banks. The times I have had theCEL go off is if it s been a few short drives or if I had a longer drive at night at cooler temps. My scanner does have a misfire counter in the test section and I have pulled it up before and it had misfires on every single cylinder.
As far as the EGR it s located on the back of the left cylinder head and it s very possible the smoke was coming from there since it s that general area. Also as far as the wiring harness goes, it runs from the PCM on the passenger side to over the top on the cylinder heads.
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Sunday, August 2nd, 2020 AT 4:09 PM
Tiny
4DRTOM
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Good morning,

With such random changes, inconsistencies with the codes with the parts that are now new. Besides the heat the ECU is the other commonality. A good visual inspection of the ecu's circuit board is in order. I'm uploading the jeep ECU showing the injector IC on the board notice the circled chip which is an example of a burnt chip. The 3 chips circled are the ones that run the injectors each chip runs two injectors. A cheap junkyard ECU may be in order.
Tom
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Tuesday, August 4th, 2020 AT 8:08 AM

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