i have been fighting this rough idle issue for about 2 months now. i have change everything under the sun (iac valve, fuel/air filter, pvc valve, cleaned t/b and ran injector cleaner through it-nothing) the funny thing about the rough idle i have been having was that in neutral and park it would idle fine. in gear after driving 15 plus miles and then stop at a light it would drop to 450rpm and act like it wanted to die. but today my check engine light came on. took it to autozone and they received a sensor 1 bank 1 (p0133 code) he said that it was the sensor on the side of cyc. #1 before the cat. converter.

question #1 does this sound right and where is this located?(ok i slid 2 into one... sorry)

question #3 could this code just be an affect of whatever is causing my rough idle?

thanks for the help guys all your input is exteremly helpful.....

 

I too have been fighting the rough idle. The sensore is in the exhaust pipe just below the manifold, easy to change. Also yes that can cause you problem. Mine just got fixed yesterday, it was the computer program needed to just be updated took 10 mins idles great know. Also found out from ford that some of the motor mounts cause rough idle because the rubber is to hard they have new ones now to replace the old ones.

 

belly boat thank you for your reply i have bought the new sensor but have not installed it yet . while driving tonight the engine light went off? i thought once the code has registered it stays until you either reset the code or fix the problem (correct me if i am wrong). i am replacing the sensor tomorrow hopefully that will help. about this computer update how did you find out about that and how much did it cost to have it done. my truck is a 97' should i have it done? also is the rubber on the mounts a big job to tackle? how much would that cost? .........thanks again

 

Although my CEL came on and has not gone off except for when I reset the computer it can go off after it came on. I've seen that before.
If it is the o2 sensor I've replaced all 4 of mine and they are very easy with the o2 socket or even the right size wrench...

Good luck
Stan

 

I had taqlked to my ford dealer. It cost me nothing because I bought my truck form them. I live in Canada so our cost will be different. The engine mounts were a recall in the 2001 models so this wont apply to you.Call your ford dealer about computer thing.

 

ok i replaced the o2 sensor just before the cat.converter on the passenger side and so far so good. i have not had a rough idle yet. but i have only driven maybe 10 miles max. since i have changed it. the rpms have gone up from 500 to about 550-600 in gear w/ foot on the brake. still seems a little low to me but oh well. thanks for the input guys......

 

have you had a chance to put any mileage on the truck? is the problem solved? i'm having the same problem, but i can't get a code... i changed everything else...

 

i have put a few miles on since i have changed the o2 sensor and i have NOT had the rough idle yet. but like i said it still seems to me that it should be idling higher than 550-600rpm under a load w/ the brake depressed. but so far so good. i will post here again if i start having the idle issue in the next couple of days. the only things i have left to do is change out 1-2 more sensors and a plug and wire change. (i will be doing the plug and wire change in the middle of the month of october.) after that if the idle issue arises again i don't know what i will do.

 

your truck SHOULD idle at 600 rpm.

O-2 sensors (Which is what you replaced) are very tempermental when they get old. When you first start your truck in the AM your v-8 produces so much water that they-O-2 sensors-get soaked and if you don't drive it very far they stay wet so when you re-start they throw a code. Your CEL prolly went off when the O-2 sensor dried up!

you should also replace the other O-2 on the other side because now you are sending the PCM two different values. Old O-2 versus new O-2.

 

I recently bought a used Expedition with the 5.4. It has intermittently run very roughly and will not maintain an idle uless you apply extra throttle. It goes into this bad running mode intermittently, runs fine for a few days or even three weeks, then bad idling again for a few short trips.
I'm afraid to let my wife drive it as when it fails you stall when cornering with your foot off the gas, the power steering becomes VERY heavy and a safety concern.
I had autozone check the codes after the last failure, it cleared up 2 miles before I arrived at Autozone, they found no stored codes. I bought a Code Scanner to have ready and waited 7 days, this morning it finally failed again and I was ready. Unfortunately it finds no codes! I drove 15 minutes to work, rough running and wanting to stall at every light all with no codes found.
It feels like one or even two cylinders not firing. When it is not in this failed mode, the truck runs perfectly and gets 18 MPG highway.
How should I proceed? Can a mechanic find the problem with no codes and this very intermitetnt behavior? Right now it is in failed mode but by history will clear up probably after a few more miles. Warmup?

Any help much appreciated, thank you.

 

I would seriously consider checking out the injectors. I had 97 F-150 that was exhibiting the same behaviors and I had one injector that was working and then not working some times...had to replace the injector and plug and wire for that cylinder as well as the O2 sensors. The o2 sensors adjust to lean out or richen the fuel mixture etc...when the injector would stop working, raw fuel was just dumped intop the cylinder and thus out through the exhaust and it contaminated both o2 sensors to the point where they had to be replaced.....the error codes are good but they don't tell you what the problem is, just what to replace to diagnose the real problem ( in my case it was the injectors ).

 

having some what of a similar problem, just to the extent to where it is dying out. idles rough, and sometimes just feel like it lacks power...

how did you find out which injector was bad? can you check the plugs for signs?

 

i meant to write that it is not dying out. just drops rpm's to about 450 or 500 and shakes badly, the rpm's never drop will actually driving, but sometimes lacks power, in the lower range.

 

I have had the rough idle issue for a year now. The dealer has put in an EGR valve, an Idle air flow sensor, Another EGR, and has cleaned and flushed the fuel system. They tell me that if they dig into it deeper it will cost me an arm and leg for diagnostic costs. Until it throws a code i'm screwed.

 

Try re-setting the computer so that it will learn a new idle pattern.