so heres the deal my 99 chevy K2500 OBS 350 V8 has the check engine light going off and on. the code is system too lean bank 1. it will come on for a week or so then it will be off for a month or more. it just came on today and it hasnt been on since july. the only thing i have noticed is it pings when i start it up when its cold. i tried cleaning the mass air flow sensor and it didnt help. im wondering what else the problem could be. anybody else have this problem
thanks
It sounds like you may have a faulty oxygen sensor. Does it say "bank 1 sensor 1 or bank one sensor 2" or does it just say bank1? Many vehicles have more than one sensor on the bank 1. With out being able to check it in person it's hard to say but the oxygen sensor is probably a good starting point.
p0171 is the code again its "sytem too lean bank 1". it doesnt say anything about an oxygen sensor so i have no idea what it could be.
The oxygen sensors tell the computer if the system is too lean or too rich.:)
p0171 is the code again its "sytem too lean bank 1". it doesnt say anything about an oxygen sensor so i have no idea what it could be. Before you spend $100 on an O2 sensor you may not need, first check for an exhaust leak between the manifold and the cylinder head on the driver side (this is the "bank 1" side). With an exhaust leak, it will allow extra oxygen to enter the exhaust ahead of the O2 sensor which will cause the ECM to think that the left bank is running lean.The tip off here is you also said it "pings" when you start the truck cold.The "pinging" could be the exhaust leak.
B&B i was just thinking today that could be the problem.i have noticed the ticking from the drivers side of the motor under accelleration. my buddy had the same problem on his F-150 when his header gasket went bad. now i just need to decide if i should spend the cash on a new set of headers or a new manifold or just try a new gasket and see if that helps. thanks for the help guys
It could be an intake leak too, getting too much air for the gas supplied by the EFI. My Windstar would throw the same code (statement). They replaced the intake gaskets under warranty and it never came back.
well this is wierd but ever since i cut out the mufflers and put in straight pipes the engine light went off and the truck has way way more power i think the mufflers were clogged because when i shoke them around there was a bunch of loose crap rattling around inside them. i think this was why my truck would rattle was just because of the mufflers.

Been thinking about doing a torsion bar key lift to pick the front up a little. I am cranked 5 turns now with stock keys. Will re-indexed keys allow me to get a little more lift without limiting the travel, or will I limit the travel no matter what? I'm only concerned because of hanging the 950lb Blizzard off it. I don't want to have the front end too tight, then load it so that there is no front suspension.
I think I am right in thinking the new keys will give me more room to adjust, but I have trouble picturing the front end geometry. So anyone with real frontend experience that can clarify it for me, I appreciate it.
The new keys only help if the old ones won't lift high enough. If you have your tb bolts cranked all the way in and you still have travel, then get the keys. On your upper control arm at the back there is a stop and you should be able to get your fingers betwwen it at max height. I wouldn't even go that high because your cv's will be on a really bad angle for plowing. IMO I can't see you needing keys. Good luck.
big giant bandaid for the problem.
turn them a bit for the plow and if you need more for other stuff. get a body lift or other fix of some kind.
my boss had me install a key kit. he had me take it out in 3 days. he said it sucked so bad he couldnt take it anymore.
You might want to reconsider using the re-indexing keys and just replace the T-bars with bars of a higher capacity to help hold the weight of the plow. Do you know which bars are under your truck now? Check them to see if the tag is still on either one of them, if you can read the two digit code on the tag you can identify the weight rating of the bars and then upgrade them to a heavier bar.
What do you mean tag? Is that something that would be stamped into the bar itself or? This would be something I am interested in. Can anyone tell me more?
The bars would have originally had a decal with letters printed on it wrapped around it. This is used to identify the weight rating of the bar during assembly of the truck. The tag will have a small series of numbers..this is the actual part number of the bar.It will also have a 2 digit letter code..(ie YB,GH, LF) this identifies the weight rating of the bar. GM has 18 different T-bar sets with each set having different weight ratings for different trucks. The bars are actually stamped with the 2 digit letter code also but they're stamped on the end of the bar and it's very difficult to see with the bar installed on the truck.That's why the tag is handy if it's still there...
Thanks B&B, What is the biggest i could put on a 2500hd gmc with a duramax?
You might want to reconsider using the re-indexing keys and just replace the T-bars with bars of a higher capacity to help hold the weight of the plow. Do you know which bars are under your truck now? Check them to see if the tag is still on either one of them, if you can read the two digit code on the tag you can identify the weight rating of the bars and then upgrade them to a heavier bar. He has a 1 ton truck. How is changing the bar going to help with lift. If he is concerned with lift it is the tb adjusting bolt he has to mess with and once this bolt is all the way in and your truck is not high enough, that's when you get new keys. I'm not sure what you do to half tons, I only know heavies. Please correct me if I'm wrong, I just want to know how changing the bar on a 1 ton truck is going to give him lift.
I am just looking at it, so when i mount my boss vee on my truck it wont sag as much. Plus I have timberns on it also, but I am just wanting to help out the front end.
I am just looking at it, so when i mount my boss vee on my truck it wont sag as much. Plus I have timberns on it also, but I am just wanting to help out the front end. Trust me the bars and keys on a 2500 Hd are fine for what you are doing. My 98, 01 and 02 have 9'2 Boss's on them since new and have had very little trouble with them. Put a Cognito steering and pitman upgrade on your truck and that will help your front end out. Saggy front ends are just a problem us GM owners have to live with. I love the GM front end. JMO
He has a 1 ton truck. How is changing the bar going to help with lift. If he is concerned with lift it is the tb adjusting bolt he has to mess with and once this bolt is all the way in and your truck is not high enough, that's when you get new keys. I'm not sure what you do to half tons, I only know heavies. Please correct me if I'm wrong, I just want to know how changing the bar on a 1 ton truck is going to give him lift. T-bars are just like any other spring, the stiffer they are the less they'll sag when weight is applied. When you just turn the adjuster bolt up on the existing bar, all your doing is changing the height at which the suspension "starts out" before the weight is applied.Your not changing the weight capacity of the bar or the torsional stiffness of the bar. If your looking for increased weight capacity, you change the bar, if your just looking for additional height, you change the setting or the torsion keys. Like I mentioned in my previous post, GM has 18 different torsion bar ratings, just because a truck is a 1 ton, it doesn't mean it has the stiffest bars already under it.
Thanks B&B, What is the biggest i could put on a 2500hd gmc with a duramax? The stiffest bar that GM makes is the 9054 (Code "XG") max torque bars. GM rates their bars by "max torque" not by actual weight capacity. They range from 1933 max tq. all the way to the 9054 max tq. bars. That's why you need to find out which bars your truck currently has so you know how far up the scale you need to go. I've done much, much research on T-bars and the majority of 2500Hd's seem to use the 5826 (Code GF) or the 6790 bars (CodeGG) but it does depend on how the truck was optioned.
Thanks B&B I wasn't really understanding everything completely I guess. If you put the heavy bars in I guess it will ride rougher when the blades off then? So there's no standard bar for a 1 ton, they can pick from a few?
I have them cranked 5 times right now, it sits level, looks good and rides very well. I just want to lift it a little more, and was thinking about doing the keys just for lift and to fit 33" tall tires. I've carried the Blizzard two winters now with no problems, but I wouldn't want to switch to different keys and lose suspension travel or capacity. I don't know which bars I have, but I don't think a diesel K3500 would come with wimpy ones. I was planning on a body lift instead, maybe I'll just go that route instead. Lot more work though.
Thanks for all the replies, even though I'm still confused.
Dan, just count the threads, then crank it up. You won't hurt anything. I use to crank mine up every spring to get my 285's on and then crank them back down for winter and stock tires.
I have them cranked 5 times right now, it sits level, looks good and rides very well. I just want to lift it a little more, and was thinking about doing the keys just for lift and to fit 33" tall tires. I've carried the Blizzard two winters now with no problems, but I wouldn't want to switch to different keys and lose suspension travel or capacity. I don't know which bars I have, but I don't think a diesel K3500 would come with wimpy ones. I was planning on a body lift instead, maybe I'll just go that route instead. Lot more work though.
Thanks for all the replies, even though I'm still confused. OK, so your just looking for a little more height, not weight carrying capacity? The keys may add a little height but they wont add any additional travel OR weight capacity. Check you current adjustment on the adjusting bolts and see how much threads are left on the bolt AND check to see how much down travel is left in the suspension before you waste any money on the replacement keys. You only have so much travel in the suspension and if your already close to being "topped out" on the stops at the upper A-arms, the keys won't give you much additional height.

Anyone know what has to be done to remove the new Body style 2500HD headlight assy. to plug in plow light harness. Pics or diagram would be very helpful.
what type of plow are you installing..?? the headlights are held in by 3 bolts.. two on top and one on the insdie bilter to the fender.. you can access the left from under the fender and the right you have to unbolt the inner fender.

How do I adjust the parking brake on my '04 2500HD? Right now the parking brake won't even hold back a fart. :help:
Sean
How do I adjust the parking brake on my '04 2500HD? Right now the parking brake won't even hold back a fart. :help:
Sean Hi Sean
There is no adjustment on the HD parking brakes. You must have either a bad or wrong cable. It should when you push the pedal to the floor a bit of pressure on the pedal. If it goes down easy then there is something wrong.
Regards Mike
Thanks for the info. The pedal goes all the way to the floor without problem, but doesn't hold the truck. Guess I'm going to the dealer.
Thanks.
Sean
Sounds like the cable broke? Is the truck a manual? I have a auto and I wouldn't even think of using the parking break unless my tranny went out or something like blowing a rear end.
Parking brake is to be used at inspection time only! I sure hopes it pops back afterwards.
I use my e-brake whenever I park my truck on anything more than a moderate incline. Saves the tranny from havnig to hold 3 tons of truck and keeps me from having to fight to take it out of park.
GM had a recall on these, but only if you have a manual tranny! The actuators, and the cables rust prematurely. The auto tranny vehicles use the same setup, but GM got the folks at NHTSA to recall only Manuals, 90% of GM trucks are autos, now doesn't that spell payoff!
In my case they stuck "on" the last time I applied them, and wore the shoes down. I had to buy 2 cables($$$), 2 shoes($$$), and lube the hell out of the actuators(the cam that spreads the shoe apart) to get everything working again.
P.S. I always applied my parking brake(use-it-or-lose-it), and they still rusted stuck. I agree with Grandview - Apply only when being inspected!
i bet its rust in the edrums on the rotors and the material is gone on the shoes. or blown axle seal with oil all over. i see it all the time.
My truck is an auto. I found out it didn't work when my truck failed inspection:mad: Sweetk30, I think you may be right. I think I might have a blown axle seal because there is definately oil seeping out one side. BTW how much of a PITA is it to fix a blown seal?
Thanks
Sean

I am getting ready to take mt 07 2500hd classic 6.0 with 4:10 across country from Indiana to Vegas. I will be pulling a 24' enclosed trailer loaded . total trailer weight about 8500 pounds. My question is the tow/haul mode do I use it of not. Let me know your thoughts on why or why not.
I would use it. Tow haul changes the shift points to a better RPM, uses the enginge to break, and uses the tourqe convertor to its potetintal.
Nicely said. Everytime I am towing a trailer I hit that button. And for you it will work great going thru those mountains. What are you hauling?
tow-haul mode
it downshifts for you, helps you braking
and keeps you moving when going up.
remember on really steep hills, throw it in manual and downshift it to a good point
DON'T BURN UP YOUR BRAKES ON STEEP DOWNHILLS
flatlanders don't get how big mountains are out here.
I can think of a couple 5 to 10 mile 6% downgrades on freeways off the top of my head.
downshift her, throw on the blinkers and putz along in the right lane at 30mph.
You will eat your brakes otherwise.