# [SOLVED] Is it bad to run a truck without a o2 sensor?



## willmon18 (Apr 22, 2006)

I have a 98 Dodge RAM 1500 4WD pickup truck and when it is going up hills and accelerating past 50 MPH it likes to vibrate and buck all over the place. At one point it just decided to stop running and wouldn't start anymore. I took it to a shop and they replaced the distributor and the cap and it runs now but it still does this as I couldn't afford to get a new o2 sensor and the wires that go to the o2 sensor that are on there are too short to solder back together as they were cut when the catalytic converter was removed and replaced. Also there is some type of oil leak causing one or 2 of the spark plugs to get fouled up fairly badly and I think I am going to get some antifoulers to temporarily fix that issue. What I am wondering is that if running without an o2 sensor can cause the cylinder walls to get torn up really bad from what I heard. If so then will getting a new o2 sensor fix the issue and it run fine even if they walls have gotten torn up very badly or not.


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## Wrench97 (May 10, 2008)

*Re: Is it bad to run a truck without a o2 sensor?*

Without the O2 sensor the truck will run in a pre-programed "limp home" mode you'll get terrible fuel mileage, no power and will probably damage the converter if it already isn't burn out or melted shut.

Are the plugs oil fouling(wet oily deposits) or gas fouled black dry deposits or smell like gas if wet?


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## willmon18 (Apr 22, 2006)

*Re: Is it bad to run a truck without a o2 sensor?*

I think they have oil on them specifically and gas fouled. My brother was saying if they have oil on the plugs the block may be cracked.


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## Wrench97 (May 10, 2008)

*Re: Is it bad to run a truck without a o2 sensor?*

No oil means either piston rings or valve guides/seals are failing.

Gas could be from the O2 sensor not being there and running rich or injectors leaking.


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## willmon18 (Apr 22, 2006)

*Re: Is it bad to run a truck without a o2 sensor?*

Ok, well I guess it could have been gas then. Anyways we got the o2 sensor replaced and the check engine light is out now. Just once it gets to 45 and the rpms are below 2000 then it starts to vibrate the whole truck still. Is it possibly the transmission or even since the oil is leaking in some places getting into one or 2 of the spark plugs that is what is causing it to partially misfire? Also when it is stopped and idling the rpms move a small bit up and down and I have never notice it do that when everything was running fine on it.


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## Wrench97 (May 10, 2008)

*Re: Is it bad to run a truck without a o2 sensor?*

If oil was fouling the plugs they would stay fouled and miss all the the time, is the vibration coming from the motor or the drive line?
Vibration around 45 I would check the driveshaft(s) u joints, if it's 4 wheel drive check the front ones too.


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## Basementgeek (Feb 7, 2005)

*Re: Is it bad to run a truck without a o2 sensor?*

When was the last time you replaced plug wires?

BG


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## willmon18 (Apr 22, 2006)

*Re: Is it bad to run a truck without a o2 sensor?*

Very recently. Everything was replaced the wires, the plugs, the cap and rotor. Not sure about the distributor itself though as the mechanic just replaced the cap and rotor I did the plugs and wires myself. And I don't know where the vibration is coming from. Just when going up to 45 with the RPMs at the normal 1.5k the truck just starts to vibrate. If I let off the gas a little it doesn't vibrate as much. But when I push the gas enough it starts to misfire and eventually the RPMs go up above 2k and the vibration stops. I will see if I can look at the drive shaft and ujoints when I can. And as a note once the 4 wheel drive stopped working. I could get it in 4wd and the light would never come on no matter what. Also when driving it with it in 4wd it felt like it wasn't in 4wd. My brother in law did something and it worked so I never thought of anything afterwords.


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## willmon18 (Apr 22, 2006)

*Re: Is it bad to run a truck without a o2 sensor?*

Well I found that one of the plug wires had a metal ring out of place or something like that and it wasn't coming in contact with the plug. It seemed to of cleared up the idling and the needle for the rpms wasn't going so crazy but it still vibrates so I am thinking maybe some of the other wires aren't on correctly as well. Will something like this cause the check engine light to come on or possibly show which plugs are misfiring on a test?


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## Wrench97 (May 10, 2008)

*Re: Is it bad to run a truck without a o2 sensor?*

It could, you have to check to see what codes are active.


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## willmon18 (Apr 22, 2006)

*Re: Is it bad to run a truck without a o2 sensor?*

Well I had recently took the truck out and the check engine light came on again. And at auto zone they said it was the downstream o2 censor that was making the light come on. Well after I put gas in the truck later the light had went off. But now when going down the road at 55 as long as the light isn't on it doesn't really vibrate that much at all. So I think it is probably fine now and was just the upstream o2 sensor and the wires on the plugs that were messed up. As it seems to run great now especially in idle.


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## wolfen1086 (Oct 4, 2007)

*Re: Is it bad to run a truck without a o2 sensor?*

if you replace deth O2 sensor the codes stored in teh computer need to be cleared, auto zone can do that with their code reader but you have to ask them.
Your gonna wnat to locate and fix the ol leak asap, but the plugs wont; get oil fouled from inside unless your leaking oil internally


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## SABL (Jul 4, 2008)

*Re: Is it bad to run a truck without a o2 sensor?*



Wrench97 said:


> No, oil means either piston rings or valve guides/seals are failing.


Which plugs?? If they're near the rear of the engine it could be what Wrench97 says. I once let an engine sludge up and the heads wouldn't drain with the oil galleys plugged up......rear plugs fouled in only a few miles.


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## Midnight Tech (Dec 31, 2001)

wolfen1086 said:


> if you replace deth O2 sensor the codes stored in teh computer need to be cleared, auto zone can do that with their code reader but you have to ask them.
> Your gonna wnat to locate and fix the ol leak asap, but the plugs wont; get oil fouled from inside unless your leaking oil internally


Wolfen, they can't clear codes...policy.


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## Corday (Mar 3, 2010)

*Re: Is it bad to run a truck without a o2 sensor?*

If you just clear the code yourself it will show not inspection ready. Drive it through a few cycles after replacing the sensor and the code will clear. The other option is an ODBII reader which will clear the code.


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## Basementgeek (Feb 7, 2005)

*Re: Is it bad to run a truck without a o2 sensor?*

Parts America will not clear them either.

BG


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## wolfen1086 (Oct 4, 2007)

*Re: Is it bad to run a truck without a o2 sensor?*



Midnight Tech said:


> Wolfen, they can't clear codes...policy.


WOW, Advance here can if you ask them to, but than thats why I got a el cheapo code reader, so I can do it my self


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## willmon18 (Apr 22, 2006)

*Re: Is it bad to run a truck without a o2 sensor?*

Well sorry for the late reply. The truck is actually working great now. The only problem I am not so sure of is that when accelerating it seems to hesitate a bit. Basically it revs up and down a little as if it isn't getting gas through the lines very well. Eventually when getting up to speed it stops and it runs smoothly. It is actually so quiet sometimes that I think the engine died but it didn't. So I am going to probably be looking at the fuel filter and see if it is dirty or possibly a little clogged up. Anyways if someone could mark this as solved and close it that would be great thanks.


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## dannpp2012 (Aug 5, 2012)

*Re: Is it bad to run a truck without a o2 sensor?*

With out the o2 sensor the truck won't run right.


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## willmon18 (Apr 22, 2006)

Not from what I heard. Having a bad o2 sensor is probably the same as just removing it. It will just be in limp mode.


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## Basementgeek (Feb 7, 2005)

I still think not having one will effect performance, gas mileage. 

BG


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