02 Explorer Shudder at cruise and idle

[hondo2359]

Hello! This is a first time post. Hope I'm posting this in the right spot. I have a 2002 Explorer 4.0 4wd. It has 189k on it. It has been shuddering/sputtering when idling or at a stoplight off and on lately and while cruising it will sometimes have a shudder and when i press on the gas it doesn't always respond right away. If i press harder it will then catch and take off. (While pressing on the gas while it it doing this the RPMs don't respond accordingly) It is a intermitten issue. Also it may just be me but it seems there is a lack of power. I haven't had this car for very long and have always had cars or small pickup trucks so this is newer to me so I'm still figuring out what feels normal for this vehicle. Thanks for any help!

 

[Limited02]

After the vehicle has run for 20-30 minutes, does it idle/run normal? Do you have a check engine light?

Since you just bought it and it has 189K miles on it, I would change the spark plugs and wires. Changing the fuel filter and cleaning the IAC/MAF sensor would be a good idea as well.

 

[Number4]

Is the shudder engine related, or drive related? At stop or idle, does it feel as if the transmission is trying to move the vehicle?

 

[hondo2359]

I have changed the plugs this past weekend. I do have a check engine light but the only thing it showed was a O2 sensor which I will be changing this weekend along with the fuel filter.
It seems to do it more after it is warm. If its a quick drive you don't feel it but as you drive it longer you seem to notice it more. It seems more engine related to me. When at a stoplight it seems to be shuddering almost like its dying then it catches, and the same while cruising just slight shudders and no power when the gas is pushed. Do you think this is more of a fuel issue? I will clean the MAF and change the filter and O2 sensor this weekend and I guess I will know more then.

 

[Limited02]

I have changed the plugs this past weekend. I do have a check engine light but the only thing it showed was a O2 sensor which I will be changing this weekend along with the fuel filter.
It seems to do it more after it is warm. If its a quick drive you don't feel it but as you drive it longer you seem to notice it more. It seems more engine related to me. When at a stoplight it seems to be shuddering almost like its dying then it catches, and the same while cruising just slight shudders and no power when the gas is pushed. Do you think this is more of a fuel issue? I will clean the MAF and change the filter and O2 sensor this weekend and I guess I will know more then.

Since you say it's more noticeable when warmed up, I wonder if your coil-pack is going bad? I think the 4.0's have a coil-pack that all 6 wires go to? Think of the coil-pack getting hot and the spark getting weaker.

First change the things you mentioned and report back.

 

[hondo2359]

I had a friend of a friend who is Tech at a Chevy Dealership hook it up to his fancy computer and these are the codes it spit out.
P0113
P0152
P1151\
Lean and Rich Codes for Driver side
P1152/
P1504 Idle Air Control Valve

He tested compression with the computer and all were in specs. The major issue was the driver side (Bank 2) sensor 1 was reading absolutely zero. Getting nothing from it. I did some testing. I disconnected the sensor and checked the connection. I am getting a good ground and 12v to the sensor, also one of the other wires I can't remember the color was reading 6.4v. So everything that I can tell shows the sensor is getting power and whatnot. Is there a way to test the acutal sensor or should I just replace it since I know its not reading anything and I know I am getting power to it?
Also the idle air control valve code was spit out. I have taken it off and cleaned it. I wasn't sure how to tell if it is good or not. What are some ways to test it or should I just replace?

 

[Number4]

A bad O2 sensor will screw eveything else up. If you've stated that an O2 is bad, then don't touch anything else until you've fixed the sensor.
The longer you wait, the more likely you'll have cat conv issues. Fix the O2.