[AT] O/T Tow truck OBD II question

charlie hill chill8 at suddenlink.net
Wed May 21 20:51:57 PDT 2008


Thanks Steve,  the O2 numbers were really just an example of what kind of 
data I'm looking at.  It's not setting a code that indicates an oxygen 
sensor problem.
However, there has to be a source of information out there related to the 
ranges of all of the sensors along with some pictures of what the graphic 
representations should look like.  That is primarily what I'd like to know.

As for error codes the only one I'm having an issue with is a 0171, lean 
condition, on Lynn's Buick.  I know how to find that problem.  I'll just 
have to look a bit.

Charlie
----- Original Message ----- 
From: "Steve W." <falcon at telenet.net>
To: "Antique tractor email discussion group" <at at lists.antique-tractor.com>
Sent: Wednesday, May 21, 2008 11:24 PM
Subject: Re: [AT] O/T Tow truck OBD II question


> charlie hill wrote:
>> I just bought an OBD II code reader that interfaces with my notebook
>> computer.  It's pretty impressive and gives all sorts of charts and 
>> graphs
>> of engine sensor operation.
>> I'm happy with it..... almost.  The problem is that I don't know how to
>> interpret all of the data.  For example the graph generated by one of my 
>> O2
>> sensors seems very erratic by comparison to the one down stream behind 
>> the
>> converter but I don't know how it should look.
>>
>> Does anyone know of a book that explains the parameters of the different
>> engine sensors and maybe has pictures of the ocillascope (sp) graphs?  I
>> finally got tired of paying inept mechanics to throw parts at a problem.
>> I'm intending to teach myself how to diagnose this stuff to the extent 
>> that
>> it can be done.
>>
>> Charlie
>>
>> _______________________________________________
>> AT mailing list
>> http://www.antique-tractor.com/mailman/listinfo/at
>>
>>
> You just discovered the problem with the PC based units. Way to much
> data with no explanations. They are GREAT for watching the data stream
> though.
>
> Anyway. The upstream O2 is actually measuring the exhaust stream and
> it's signal is the one controlling the mix through the ECM, as such it
> will bounce around a LOT.
>  The one after the cat is basically there just to monitor the output
> from the cat. It will stay in a close range as long as the cat is doing
> it's job.
>
> Drop me a note off the list and I can give you some numbers and probably
> interpret the data a bit. Plus a few links that might help you out.
>
> -- 
> Steve Williams
> Firefighter,EMT, Fire Police
> VanHornesville Vol. Fire Dept
> _______________________________________________
> AT mailing list
> http://www.antique-tractor.com/mailman/listinfo/at 




More information about the AT mailing list