Chevy engine miss.Help please. Its fixed!!!!

[HntnFsh]

I have a 98 Chevy Silverado 2500  4x4 ,350 V8 Auto

Its been running great.Last night I shut it off.All was fine.This morning it started to run terrible.And still is.

I borrowed an OBD 2 code reader.Its putting out a P 0174 pd code. Right bank lean.  

If I'm reading right.That means the code is ongoing.So I think it has been there since before the engine started acting up.

I honestly dont know much about code readers.But it looks like it has a monitor system.To leave plugged in for awhile when driving the truck.

There are a few things I'm wondering about. Am I correct about the code?

What would cause that particular code?

Do you think its related to my engine miss?

One thing I noticed.The right bank catalytic converter is significantly hotter than the left bank.I'm wondering if its getting plugged,causing that bank to run lean and throw the code I mentioned above.

Can you advise me on how to use the reader to moniter the system? Or should I?

I'm headed out to check plugs etc.Supposedly they havent been in for long.I bought the truck a few months ago and the previous owner had tuned it up.He is a mechanic.But I know plugs can go bad anytime.

All wires look good.

If its a sensor of some sort it seems like it should throw a code.Is that right?

Sure do appreciate any help you have to offer.

Thank You,

HntnFsh

[Woodchuck]

it is a lean code, will make the cat on that side hot if it is lean. check for vacuum leaks, use can use brake clean to spray around the intake if you hear the idle change, you are getting close. if it is getting the cat that hot, you should not drive it much, can burn a valve. i would think if it were some sensor or a clogged fuel filter it would be both sides 

[FC]

Look for a vacuum leak but if you don't find something obvious just take it to a shop, it will be cheaper for you in the long run than if you just start swapping parts.

[hughjorgan]

o2 censor could have gone bad

[the1rod]

o2 censor could have gone bad

dosent an o2 sensor usually throw its own specific code?

[lee]

Hi,

A right bank lean condition could also be caused by a failed Fuel Injector on that side. This would also account for the bad idle and hot cat.

Checking the plugs is a good idea. When checking look to see if one of the plugs is "whiter/asher/drier" than the rest on that bank. If so, swap that plug to the left bank and see if the code follows. Also, you can swap that injector to the left side to see if the code follows. Troubleshooting can be a PIA!!!!

As stated a vac leak is also possible. The Intake gasket on this engine is problematic.

Does yer truck have an O2 sensor for each bank? If so, swap them and see if the code follows.

Most code readers only take a "snap-shot" of the reported code. They are not "live" insturments. After you do any repair activity, clear the old code and run it to see what code re-appears.

Good luck and let us know how it goes.
Lee

[jeepster]

Hi,

A right bank lean condition could also be caused by a failed Fuel Injector on that side. \

thats what i was gonna say. ive monkeyed enough on a suburban that the owner insisted keeping running past 350k miles...


did the truck sit for a long time/allow varnish to build up?


injectors can be a beyatch to do if you havent done them before, ive never done gas, but diesel injectors i have.

try the brake kleen on the vaccuum lines, check  "distributer" make sure everything is plugged in.... what about the MAF sensor?


i had an old s10 that ran like crap, i dumped 1 bottle of marvel in the oil, 1/2 a can of seafoam down the carb w the truck running and the other 1/2 in the gas tank, then dumped an octane booster in the gas tank at about 1/2 a tank.... needless to say it fixed itself...

 

[jackelope]

this'll get you straight...

[FC]

An o2 won't cause a miss...ever.

o2 sensors only throw a specific code for actual part failure, a lean bank is not an o2 problem.

The engine in question uses a central fuel injection system...You cannot switch and ditch injectors. Being as o2 sensors have a nasty habit of seizing into their mounting bung I recommend NOT switching and ditching them around, aside from that they use different harness lengths and highly likely won't reach. The problem the intake gaskets are known for on this engine is coolant leaks due to the caustic dex-cool eating the nitrile sealing rings at the ends of the cylinder heads where the cooling jackets are located. Vacuum leaks at the intake manifold itself on this engine are rare. "Code readers" don't take a snap-shot, the vehicles ECU does and the code reader (scan tool) merely downloads it, if you could actually read live data would you have any idea of what you were seeing? The manufacturers of such tools knew that too and left live readings out of it to keep the cost of (making) the tool down. A driveability tech needs that info and an actual scan tool that will show it costs a hell of a lot more than a simple code reader.

@ the OP, if any of the magic tricks listed in this thread sounded like a good idea, take it to a shop before you break something! Once you get past looking for obvious vacuum leaks a shop is your best bet here.

All of you using brake clean on to find vacuum leaks are destroying o2 sensors...use propane, it will have a greater effect, a much safer flash point and won't ruin sensors.





Rofl Jackelope...Now you will just confuse the poor guy with a generic OBDII test!

[lee]

FC,  so you flame everyone's suggestions for this poor fella, then all you can recommend is that after a vac leak check he take it to a shop.

Hum, ..... which "stealership" do you work at? 

[FC]

FC,  so you flame everyone's suggestions for this poor fella, then all you can recommend is that after a vac leak check he take it to a shop.

Hum, ..... which "stealership" do you work at? 

I flamed no one sir but I did lay out the facts that I have learned by working my ass off for years as a driveability tech and no I don't work for a dealership nor did I suggest the OP visit one. I have seen many people who went off of apparent myths and magic to "fix" a car or truck and end up costing themselves thousands either to repair the damage they caused or by the wheelbarrow loads of parts they dumped into the thing before they lucked into fixing it. I have literally seen this type of thing happen thousands of times and if the problem in this instance is anything more severe than an external vacuum leak the owner will almost certainly be better off going to a shop. They will have all the tools necessary to work on this problem....Do you? I know I've spent over 100k on tools to be able to efficiently and effectively work on cars with the right tool for the job as opposed to using incorrect tools that damage parts or fasteners and end up costing time and money as well as ultimately requiring the purchase of the correct tool for the job.

So yeah...I recommend taking it to a shop, not because the owner isn't smart enough to fix the car or w/e other reason a person might think up but because I highly doubt he has the necessary tools and obviously doesn't have the knowledge...Why? Because he isn't a mechanic....

[JackOfAllTrades]

I sure miss carburated non emissions non computer controled engines!   

-Steve

[runamuk]

I sure miss carburated non emissions non computer controled engines!   

-Steve

me too my old 70's rigs I could not only add and change oil I could also change plugs and wires and I could actually identify the majority of components.....

My Jeep I can almost find the oil and have no idea exactly where much else is under the hood...pretty sure there is an engine in there somewhere 

most the guys replying on this thread work in "shops" I find it funny how the shop guys are often the first to respond and then blamed for trying to get business 

[jackelope]

FC,  so you flame everyone's suggestions for this poor fella, then all you can recommend is that after a vac leak check he take it to a shop.

Hum, ..... which "stealership" do you work at? 

FC doesn't work at a dealership...but I do.
I posted the diagnostic flow chart for the code. That is the proper way to diagnose it. That is why the shops charge people to diagnose their problems and why they do not throw parts at cars till they fix 'em or diagnose them for free...that and the other part FC posted about having $100k in tools to properly diagnose and fix cars.

Do you know the difference between a technician and a mechanic?




























A mechanic changes parts on a car, a technician knows why the parts are getting changed.
Have a nice day.

[jackelope]

I love the people who are broke down on the side of the freeway getting jump starts.