Is my car misfiring?

[timd50]

Hello all, recently upon cold start I hear an odd sound just barely audible over the exhaust. It’s a muffled popping noise that doesn’t seem to be in rhythm. I’ve tried to get video of the noise



Uploaded to YouTube. It’s audible if you really listen closely but it’s hard to hear. All I can think of is either unburned fuel burning off in the exhaust or a misfiring cylinder. It only happens on cold start (30-45 ambient) and seems to go away once warm. I haven’t noticed any real power loss when driving. Car has a MBRP Race catback, mishimoto intercooler, and Turbosmart Dualport BOV if that makes a difference.

Edit: for reference, I did scan it with an OBD reader and don’t have any misfire codes. Just want to know what’s going on with my car.

Sponsored

 

[3oostdmstng]

Hello all, recently upon cold start I hear an odd sound just barely audible over the exhaust. It’s a muffled popping noise that doesn’t seem to be in rhythm. I’ve tried to get video of the noise



Uploaded to YouTube. It’s audible if you really listen closely but it’s hard to hear. All I can think of is either unburned fuel burning off in the exhaust or a misfiring cylinder. It only happens on cold start (30-45 ambient) and seems to go away once warm. I haven’t noticed any real power loss when driving. Car has a MBRP Race catback, mishimoto intercooler, and Turbosmart Dualport BOV if that makes a difference.

Edit: for reference, I did scan it with an OBD reader and don’t have any misfire codes. Just want to know what’s going on with my car.

That sounds exactly like what mine was doing only upon cold starts PLUS a rough idle.

I changed spark plugs which only helped a bit.

My CEL eventually came on a couple hundred miles after the sound started, and the code it was throwing was oxygen sensor related.
Took it to Ford, they did some testings and ultimately they changed fuel injectors. Sound is gone and so is rough idle upon cold start.

Mind you, I've always used 93 octane since my ownership BUT I did buy the car certified pre-own (it was NOT a rental), so I don't know what previous owner pump. I bought the car with 10k mi and that issue came around at approx 43k mi. just to give you an idea.

My only mod is MBRP catback.

 

[timd50]

That sounds exactly like what mine was doing only upon cold starts PLUS a rough idle.

I changed spark plugs which only helped a bit.

My CEL eventually came on a couple hundred miles after the sound started, and the code it was throwing was oxygen sensor related.
Took it to Ford, they did some testings and ultimately they changed fuel injectors. Sound is gone and so is rough idle upon cold start.

Mind you, I've always used 93 octane since my ownership BUT I did buy the car certified pre-own (it was NOT a rental), so I don't know what previous owner pump. I bought the car with 10k mi and that issue came around at approx 43k mi. just to give you an idea.

My only mod is MBRP catback.

Thanks, that’s really good information. My car is also right around 45k miles. I’ll take it in. What did that run you?

 

[3oostdmstng]

Thanks, that’s really good information. My car is also right around 45k miles. I’ll take it in. What did that run you?

I bought the extended warranty and thought I'd have to pay the $100 deductible, BUT it was FOC!
The new injectors/labor/loaner car were all covered under powertrain warranty (which ends at 60k).

Sponsored