p0300

Had P0300 come up finally after battling rough idle past few weeks. 2018 GT MT-82, Car will idle pretty rough on cold starts seems fine a WOT, I’ve noticed at idle my AFR bounces from around 14 then goes to 20 after idling for about 15 mins then will go back to normal. Also sometimes feels...

Hi everyone! I have a 2015 mustang gt with about 64k miles, its got a tune from lund but other than that its stock. ive been chasing a misfire for a while now that mainly happens at high rpms at wot and i finally got around to pulling all the plugs (again) and doing a compression test. heres a...

Random misfire at high rpm... p0300 Changed spark plugs Going to do cat deletes tomorrow w big daddy defoulers Did some idling in the driveway and took some live readings of o2 sensors. I thought it was strange to see some negative voltage

I am looking for some advice on dealing with a misfire issue. Sorry it's a long post... but I think the details matter. A little history... the car is a 2019 Mustang Roush RS3 with an A10. It is a late build so it had the 2020+ phase 2 heat exchanger installed at Roush. The car is completely...

Well, this wasn't the outcome I expected to getting my first mustang. About 3 weeks ago I saw a beautiful 2019 oxford white GT pp1 with only 15k miles on it which I couldn't pass on. My gf's father whose a car salesman at ford had helped me get approved and get the stang delivered to his...

Let me start off by saying hello my name is Raymond and I have a 2016 mustang GT. Ok so i am getting P0316 & P0300 code. I have looked all over and can’t seem to find a problem, I did rebuild my motor because I did have low compression and my problems didn’t go away so I am stumped on what to...

Hey guys another issue sadly so was driving the car check engine light came on and p0300 multiple engine misfires. I have new plugs in the car about a month old. I checked the plugs all looked fine and didn’t smell like gas so I don’t think I have a bad coil. I cleared the code and it came back...

Isn't the nature of a misfire long term possible damage to your engine? I've seen in threads all over the web of people turning it off in their custom tunes. My question is, why?

My car is running lean and rich. Bank 1 STFT is 1.19 and Bank 2 STFT is 0.78. It’s giving me misfire codes P0300 and P0304. My car has catless headers, ported gt350 intake manifold with IMRC lockouts, gt350 TB, and 47 lb injectors. Starts up kind of rough but no loss of power and idles higher...

First let's get all the details of the car and what has already been tried before I even go into what is happening: I will take it to the dealer, I just like to be as informed as possible before I do, and the only dealer around here with an SVT certified tech has a 20 deep waiting list. 2017...

Hopefully this will save time and a headache for those of you that get this problem. I started experiencing a lower RPM misfire which was most prominent off of idle to 3k rpm. I would get an intermittent CEL which would produce a P0300 or P0308 code (random misfire or Cyl 8 misfire). The...

On the interstate headed home last night and the check engine light popped up. At this point I’m thinking “oh no, what now”. (Let it be known that I have already had to replace the original engine at 3500 miles for the ticking issue and a subtle double knock coming from the wristpins. New...

hey guys so ive done some searching on these forums but either im not good enough at searching this site yet, or nobody has ran into this specific problem. I had a 2.9L Whipple Supercharger installed on my 2016 Mustang GT, (manual) about three weeks ago. Also had stainless power catted lt...