Greetings all:

I have a 2001 5.9L with about 95k on it, and it stumbles BADLY when cold. It gets gradually gets better as the engine warms up, but it never goes away. When it's hot it only does it when you feather the throttle, but does it all the time when cold. I've changed plugs, wires, airfilter, and pcv. Can the O2 sensors (there are two....right?) go bad without the check engine light going on? Help!!!

Chad

Any ideas?
Anyone??

What engine codes do you get after it does it? You can check by turning off and on your key three times do not start it. You can read the codes. The engine light will flash. It does a seriries of flasseh example. Flash 1sec Flash 1sec FlashFlashFlash would be code 113. If it flashes code 555. that is the end of the list and it does not repeat.

Actually on a 2001 the code will read out in your mileage display. Do the key trick to get the codes but they show up in the mileage display. Once it shows "Pdone" then all the codes have been read.

have you checked for a vacuum leak? check around the base of the throttle body and around the injectors. you might have a leaky throttle body gasket or cracked o-ring on an injector causing it to lean out a bit when you 1st hit the throttle...

my truck was doin the same thing when it was cold and a little bit when hot
i thought it might be somethin major but i put new plugs and D-cap on it and it took care of the problem

you should have 4 o2 sensors.. i think 2 before the cat, and 2 after the cat depending on if you have a single cat system or 3 like my 2000 1500 ram 4x4 5.9L quad cab. in 99 they had a single cat system, i guess the 2000 models built after sept 1 1999 were changed over to 3 cats i guess to comply with CA emissions. just thought i would throw that out there because it sounded as if you werent sure as to what was sitting under your truck. Good luck with your truck. they are worth it.
shannon

Must suck to live in Cali. I have a 2001 quad cab 4x4 5.9 and it only has 1 cat and 2 o2 sensors.

yes it does suck to live in CA for smog reasons... traffic sucks here. However, where I live we are 3 hours max from 1/2 the state so we can see quite a bit on any given weekend...