Codes P0300, P0308, P0345 and P0349, when stopping at stop sign the check engine lights start to blink and I hear a loud knock coming from.

Tiny
MICHAEL5.0
  • MEMBER
  • 2018 FORD MUSTANG
  • 5.0L
  • V8
  • 2WD
  • AUTOMATIC
  • 65,000 MILES
The car was running lean due to a performance cold air intake it had because it required a tune. So, I removed it and replaced it with the OEM intake. But my issue with the vehicle is that when I go on a cruise and am speeding and accelerating fast and when I get to a stop sign the check engine lights starts to blink and I hear a loud knock coming from the engine and when that happens the car loses all power for like 5 minutes, but after 5 minutes the check engine stops blinking and the car goes back to normal. This problem happened when I had the performance intake and is also happening now with the OEM intake. I was able to scan the codes and I got p0300-p0308-p0345-p0349. I have also replaced the camshaft sensors before I got help from this website to locate the position they were in and I changed them out, also ford put a whole new PCM system in the vehicle, but they never mentioned anything about the engine knocking when I accelerate the car a lot. The car is also back on stock tune. I hope I can get some help from here. Thanks
Sunday, June 2nd, 2024 AT 7:13 PM

5 Replies

Tiny
STEVE W.
  • MECHANIC
  • 15,268 POSTS
P0300- random multiple misfires, P0308 - misfire cylinder 8, P0355 and P0349 both are for cam sensor bank 2 sending intermittent signal to the PCM. I would start with a good inspection of the engine wiring harness. Especially where it comes over the edge of the cylinder head up front. Look for damage to the loom or the tape and possibly a broken wire from the cam sensor. That harness also carries the injector controls and knock sensors. If only a couple wires were damaged it could be that the engine flexing during the drag racing is causing shorts in the signals.
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Monday, June 3rd, 2024 AT 9:30 AM
Tiny
MICHAEL5.0
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  • 5 POSTS
I have checked for all that and nothing seems to be damaged or disconnected.
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Thursday, June 6th, 2024 AT 8:07 PM
Tiny
STEVE W.
  • MECHANIC
  • 15,268 POSTS
When was the PCM replaced and was it showing the same issue before replacement? Same question on the CAI, did it have these problems before that? Trying to determine at which point the codes started. What scan tool(s) do you have?
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Friday, June 7th, 2024 AT 11:21 AM
Tiny
MICHAEL5.0
  • MEMBER
  • 5 POSTS
The PCM was replaced about 1 month ago, and the codes stayed the same, and the car kept the same symptoms, like when I get to a stop sign it sounds like its choking and it turns off, but when I switched back to OEM intake it stopped a little bit, but it doesn't have any vacuum leaks or anything.
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Friday, June 7th, 2024 AT 5:02 PM
Tiny
STEVE W.
  • MECHANIC
  • 15,268 POSTS
Okay, so, these codes were before all the work and are still there? What else was done with the CAI? This is the original engine and all? I would go over the harness, peel off the tape and loom and really inspect the wiring. Wires can look perfect but be damaged inside. I would also use a scope to check the signals coming into the PCM, The P0349 can shut off the engine, so I would look at that sensor and it's wiring first.
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Saturday, June 8th, 2024 AT 3:25 PM

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