Hey the check engine light came on in my truck today, its saying multiple misfire and running lean on bank #1. The truck is a 2004 silverado 5.3 Z71. anyone have this problem before, im just wondering what i should check first?? Thanks
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Hey the check engine light came on in my truck today, its saying multiple misfire and running lean on bank #1. The truck is a 2004 silverado 5.3 Z71. anyone have this problem before, im just wondering what i should check first?? Thanks
if it has the old style intake gaskets, they are leaking, spray brake cleaner around the intake and listen for the idle to change and locate ur vacuum leak.Quote:
Originally Posted by the boy
it does almost stall sometimes when idleling.
is it bad if the check engine light is flashing????
Flashing SES light usually means the engine is misfiring.
The flashing SES means that the misfiring is serious enough to cause catalytic converter damage. If it continues to flash you need to address the problem soon or you could experience a possible cat meltdown.
Is the change in idle when i spray the brake cleaner gonna be really noticable???? So i just spray it on the top joint of the intake where it meets the heads right??? could the leak be on the underside of the intake???
If there is a leak, the brake clean will get sucked into the leak, causing a surge at idle. And yes, you'll notice it.
Also try other things: Have your truck scanned on HPT possible. Look at your fuel trims. Check plug wires/plugs. Check coil packs. Move the driver's side to the pass side. Does the lean condition move to Bank 2? Injectors could be a prob as well. Fuel filter?
There are several things to try--good thing is that you can troubleshoot without spending money.
So i checked the intake today and no sign of it leaking, so i tried pulling each wire off the coils 1 by 1 to see if it would make a difference, each wire i pulled made the truck idle worse which is to be expected. but i checked the codes again and it had a new code: P0131 oxygen sensor circ low voltage bank 1 sensor 1. not sure what that means but it also showed the same codes as before P0171 sys to lean bank 1 and P0300 randon multiplyer cyld misfire detected. Could it be the O2 sensor on the driver side??? It idles pretty rough kinda like it has a bigger cam.....also i cleared the codes with my superchips flashpack and it ran pretty good for a bit but the engine light is now back on.....What should i try next??
02 sensor.
o2 sensor or intake gasket, if it's intake gaskets you'll notice it throwing lean codes and running big time rich. o2 sensor will do the same but its usually a lot more noticeable when its an intake gasket. So a little drop in your fuel mileage it o2, huge drop its gaskets
Yesterday when i had the truck in the shop it was throwing black LANGUAGE!!!!!! out the exaught pipes when i would rev it a little, but im not sure about the fuel mileage cause i changed the superchips selection from mileage save back to stock..
Intake gaskets. That things pig rich
I tried the brake cleaner around the intake and it didnt' make a bit of difference, could it still be the intake gasket?
you have a bad 02 sensor. replace both if you can afford to
Quote:
Originally Posted by the boy
whats your short term and long term fuel trims look like? and watch the 02 sensors to see if they are changing
Mine actually goes dead at idle, especially if coasting in neutral. It surges at idle, and has thrown the multiple misfire about 3 weeks ago. Gonna change 02 sensors and see what happens
its now showing code P0134 O2 sensor bank 1 not responding. which O2 sensor is bank 1????
I'm facing the same problem right now. I just replaced my plugs wires are on the way to me. Going to chang my fuel filter and get some injector cleaner and see what happens. I have spare coils packs so I just might change them as well and see what happens.
Drivers SideQuote:
Originally Posted by the boy
Does your truck idle real rough/surge when you start it up on these cold mornings?Quote:
Originally Posted by Chevytruck
You should monitor your STFTs while you spray the fluid. The STFTs will react even if you can't hear a change in idle speed. You can also read the Freeze Frame data for your DTC. It will tell you the parameters that existed when the DTC went set. You can try duplicating those conditions and then spray the fluid unless it only happens at 60MPH which won't too easy to repeat.
Intake gasket leaks are very hard to detect on these engines. What makes it difficult is that they only leak when the engine is really cold, upon initial startup. Once the engine begins to warm up, things expand and the gaskets seal themselves.
Damn man, good call. :thumb: Words from someone that sounds like you know what you are talking about! You need to make more posts!!!Quote:
Originally Posted by eallanboggs
So you are saying that popping your hood and climbing out to spray carb cleaner on the intake gaskets at 60 MPH would be a tough thing to do????? :lol:Quote:
Originally Posted by eallanboggs
Ah not really. We watched the firing the other day and all cylinders were missing at idle but not when I held it at 3K RPM.Quote:
Originally Posted by Beatdown Z
Not trying to jack your thread buddy, just that I am going threw the same exact thing that you are and maybe we are having the same problem and we can both get out trucks fixed from the help of the site. :)
Ran a bottel of Lucas injector cleaner (1 qt.) with 1/8 tank of gas and the code went off on it's own.
Light is back on again....
allright well im gonna try putting in a new O2 sensor on the driver side saturday, i'll let ya know if that makes any difference. and yes my truck idles rough and sometimes kindof chokes when im driving but if i put it in neutral rev it a bit it works better..
Put the new O2 sensor in today cleared my codes, and drove the truck most of the day and the light didn't come back on. Also the truck ran good the whole time, didn't sputer or anything. hopefully that fixed it.
I just had pretty much the same problem, i was coming home the other day and all of a sudden she starts sounding like a cammed out big block and the light started flashing (its been on since i holowed out my cats throwing cat efficency codes :LOL:) pulled the codes and found p0300 random missfire and p0174 system lean bank 2. No sign of any 02 codes but did like ya'll said and changed mine out and took care of it. Although the comments about the intake gaskets got me doing some research and found out felpro makes a new upgraded intake gasket set with a metal frame and rubber inserts part # MS 98016 T for my 5.3 i really like the new design seems a hell of alot more stout im working on doing a tread on replacing them when i get the time. Sorry not tryin to jack anybodys tread just hope it helps someone.
Yeah I changed both of my O2's and cleared the code as welland everything is running good! (knock on wood) I hope that resolved my problem as well.
Well its me again and my engine light is back on tonight, 0420 i think it was something about catalist threshold bank 1????something like that, im not sure but does this mean that i FUDGED my converter????? I cleared the code but im sure its gonna come back on....
Anybody know what this code means??
Google is your friend.
Troubleshooting P0420 Catalyst Code
Thats some good info Thanks Madd Maxx, im wondering if maybe this happened cause i only replaced 1 O2 sensor, and not both????
I would just replace both of them. You could have a clogged cat now also...
I have also found out that mine keeps coming do to the fact that I have a higher stall converter now and the tollerences need to be changed in the tune some.
jes i hope the cat isn't clogged I just got a new truck yesterday and i just want to sell this truck, how would i tell if the cat is clogged would it be hotter that the other one????
Throw a spark plug non-fouler or two on that O2 sensor if you want the 420 code gone. Did it on my 4.8 and it worked like a charm.
well i cleared the code a few times with my superchips flashpac, but it keeps coming on, what is a "spark plug non-fouler or two on that O2 sensor"???