Rough idle? P0171, P0174? Here's what you need to check first!!!

[GAINMOB]

Don't forgetcleaning the the MAF as well. It's a5 dollar/ 25 second fix. Sometimes just cleaning it will make big changes to how you run.

has any replaced their MAF with and upgraded aftermarket? the only one i find online is for $500...uhm...yeah...not getting that one...

 

[golflover]

I have a 98 expy 5.4 L with 275k miles. My question is can I remove the entire TB with the adapter and IAC to clean it on my bench rather than in tight quarters? I wondered if the fire wall would prevent removing the 4 long bolts on the adapter. I had a panting idle, high and low and surging. I cleaned the MAF, changed the PCV, cleaned the throat of the TB while still attached. THis improved a panting low idle, now its high 1000 to 1200. I also noticed a small seam leak in the muffler. Could this be the issue?

I figure I can really inspect the vacuum lines with everything off. Any suggestions?

 

[Monicagtx]

Thank you!

The picture was a big help...im a girl so looking at the motor
I was so lost...but I was able to fix it on my own. I was literally sitting in motor reading ur instructions on my android lol....thank u again! One more thing it helps if u have small hands!!!

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[johng]

thanks

great post, found the problem in 5 min

 

[Lane24]

Great to hear.

 

[paramore11]

Thanks for the post. this helps me lot

 

[frhunter]

Vacuum tube assembly

Thanks for the heads up. I originally thought it was MAF sensor bought some cleaner and that didn't work. Checked online found your post and did some further inspection. I found that the rubber elbows were both damaged. Going to call dealer tomorrow.

 

[98Expnewowner]

Thanxs for the info one question though is there a diffence between the eddie b edition 5.4 and the sxt 5.4?

 

[awb594]

Can't find the problem

I have a '01 Expy 5.4L with a P0174 code I have been chasing for months. I have replaced the "elbow" hose all the way to the pcv valve. Got a new MAF from Ford. Cleaned the TB replaced the plugs, new fule filter. Finally I got the light to go out for about a month and now it is back on again, same code. It has always had a rough idle but today as I was coming to a stop and the engine jumped up to about 1500 rpms on its own. I am hoping someone might have a suggestion for me.

 

[Lakerfan248]

Check / Replace Air Filter

I have a '01 Expy 5.4L with a P0174 code I have been chasing for months. I have replaced the "elbow" hose all the way to the pcv valve. Got a new MAF from Ford. Cleaned the TB replaced the plugs, new fule filter. Finally I got the light to go out for about a month and now it is back on again, same code. It has always had a rough idle but today as I was coming to a stop and the engine jumped up to about 1500 rpms on its own. I am hoping someone might have a suggestion for me.

Check or maybe even replace your AIR FILTER. I have my 99 Navigator exhibiting the same problem. I did replace the hose elbow that deteriorated overtime, but only solved the problem temporarily. Not until I replace the AIR filter that colapsed inside the housing which solved the problem. It was actually choking the engine and bent the hose where the MAF is located that I found out that it was the culprit. The air filter separated and plastic cup got sucked in. After I replace it, Check Engine light was off after I disconected the battery to reset it. Good luck.