Lower RPM driveability while cruising problems

[broke7]

I did a search and couldnt find much info.

I have noticed my car the past couple of days when im crusing in the 1000-3000 rpm range that car feels like its pulsing. Its gets noticeable around the 1200 rpm area at lower speeds in 2nd and 3rd gear. Almost like the car wants to jerk back and forth.

I had a po401 Fault code today with a SES light and I cleared the code and it hasnt come back on. If it comes back on I am gonna take it back in. I did my research and the code is something to do with the EGR system. I dont think its related unless its a large vacuum leak.

Any thoughts...??

 

[i8u]

Your egr system could very easily cause your complaint.
Sounds like your valve is sticking closed which would give you similar symptoms.

Even though you cleared the ses light the code is still stored in memory and can be axcessed through an obd-2 compatible scan tool.

I thought a P0401 was a cydinder #1 misfire code though. I must be loosing it.......:shrug:

 

[broke7]

I accesed it via the Diablosport "hellion" obd2 scan tool. I cleared it via that tool as well. It didnt detect any stored faults when done.

Thanks for the help.

Here is something I found
Scroll down and check out p0401
http://24.118.217.131/F150/obdII_codes.htm

 

[03DOHC]

Originally posted by broke7
I did a search and couldnt find much info.

I have noticed my car the past couple of days when im crusing in the 1000-3000 rpm range that car feels like its pulsing. Its gets noticeable around the 1200 rpm area at lower speeds in 2nd and 3rd gear. Almost like the car wants to jerk back and forth.

I had a po401 Fault code today with a SES light and I cleared the code and it hasnt come back on. If it comes back on I am gonna take it back in. I did my research and the code is something to do with the EGR system. I dont think its related unless its a large vacuum leak.

Any thoughts...??

Interesting. Some cars that had plugged cats used to blow the DPFE hose off.

 

[JSHTROD]

I get something similar when cruising. It's more noticable in 2nd, with very light throttle.

It actually feels like a stumble, or miss.

At first I thought it was my cats getting too hot. Then when I swapped out the mid pipe, it didn't stop.

Maybe it's a poorly gapped sparkplug?

 

[i8u]

Oh.... you have a scan tool.:beer:

I would defenately look at your egr system. The solnoid should ohm out at 20-40. Your complaints with your code description in your other thread sound like your egr is or was sticking closed.
:beer:

 

[broke7]

You have the same exact symptoms as me. Its only a very low throttle condition problem. Part throttle to be exact. I also noticed a "ticking sound" has started since the SES light occured as well, maybe its a hose?

Where is this DPFE hose?


Im gonna swap plugs within the next day or so to TR6's.

 

[JSHTROD]

Originally posted by broke7
Im gonna swap plugs within the next day or so to TR6's.

Let me know if this solves your problem.

BTW... what run is your car? YDH1 here...

 

[03DOHC]

Originally posted by broke7
You have the same exact symptoms as me. Its only a very low throttle condition problem. Part throttle to be exact. I also noticed a "ticking sound" has started since the SES light occured as well, maybe its a hose?

Where is this DPFE hose?


Im gonna swap plugs within the next day or so to TR6's.

Drivers side, back of the blower.

 

[broke7]

OK, im at work now. The SES is on again, downloaded a po401 again. I have driven about 15 miles since I cleared out the code.

I am gonna check some connections when I get home. Otherwise I have an appointment for wednesday morning for the driveability and SES light, plus my rattle coming from the right rear.

 

[Griffin]

I have the same problem :cuss:

 

[broke7]

the driveability or rattle?

 

[kj385]

I have the same pulsing at low speeds with light even throttle. I had an 02 GT before the cobra that did the same thing.:shrug: The mass air wire is clean so the only thing I can think to try is better spark plugs.

 

[Rick@Amazon]

We have been finding alot of stock cars coming in with loose hoses, throttle body to maf hose ready to fall off or close to it. Double check all these fittings to make they are tight and see if a vacumn lines could have pulled off. I bet it's something simple.

Rick

 

[kj385]

This is my 2nd complete motor in the 03 cobra. And they both run the same. As did the 02 GT. Note the miss is so light most people would not even notice it. The only other thing I can think of is the drop in K&N filter (it was in all three motors). I also tried with and with out the snorkel, it made no difference. Today I'm going to try the stock paper filter. After that it's different spark plugs.

 

[mike_b_svt]

Mine too...

Very slight hiccup, almost like a miss at lower RPMs. I feel mine when accelerating though, not when cruising at a constant speed.

Bone Stock,

 

[Griffin]

I had a miss at idle on the Lightning as well......

 

[JSHTROD]

Originally posted by kj385
Today I'm going to try the stock paper filter. After that it's different spark plugs.

My snake did it when completely stock. The paper filter won't make a difference.

 

[mike5876]

mine does it now after i put the kenne bell on..misses right at about 2400 rpm

 

[broke7]

Im thinking this could be EGR related possibly. Mine was doing it very little in the begining then it started getting worse that is when it threw the SES light and po401 code which is for "EGR flow insufficient"

I guess I will find out t-morow when I take it in.