1992 Lexus SC400 help

Thanks for the advice Ray. Well, what I forgot to mention in my original question was that my car has been scanned numerous times and for some reason the knock sensor code comes up. My mechanic of over 2 years, and the auto shop owner says just because the code comes up doesnt mean its the knock sensor that's causing the check engine light to come on. I am very frustrated with this whole situation, and trying my best not to have the lexus dealer check it out cause it could get expensive to check the problem by the dealer. After putting the 4th used air flow meter on today the car seems to have more power, but the check engine light comes on after about 2 to 10 minutes of driving. Something other than the airflow meter is causing the check engine light to come on. The code has been cleared over and over again. Any suggestions? Thanks.

Michael
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"mikesc400" <UseLinkToEmail RemoveThis @AutoForumz.com> wrote in message
news:1_632682_ee4d982d198bee62e56184ec3f4cfa15@autoforumz.com...
> "" wrote:
> > "mikesc400" <UseLinkToEmail RemoveThis @AutoForumz.com> wrote in message
> > news:1_632260_d86afc1b2b88b4358ae41b768e855bd3@autoforumz.com...
> > > My mechanic has tried almost 4 used mass airflow meters, and
> > the check
> > > engine light still comes on after a few minutes of driving.
> > Is the
> > > part the problem, or is there something else he's not
> > checking. I
> > > find it hard to believe that all of these parts are
> > defective.
> > > Please help.
> > >
> > > SC400Mike
> > >
> >
> > I'd have the car checked by an ASE certified technician, not a
> >
> > parts-changer. Someone if access to the proper manuals can
> > check to see if
> > an air flow meter is functioning properly or not without
> > having to replace
> > it.
> >
> > Whoever is working on your car probably pulled a code that
> > pointed to a
> > circuit, assumed that the part controlled by the circuit is
> > bad, and started
> > swapping parts. The proper diagnosis and repair is to test
> > the component
> > controlled by the circuit and then test the circuit itself.
> > There is a
> > chance that there is a loose pin in a connector or a chafed or
> > cut wire
> > somewhere.
> > --
> > Ray O
> > correct the return address punctuation to reply
>
> Thanks for the advice Ray. Well, what I forgot to mention in my
> original question was that my car has been scanned numerous times and
> for some reason the knock sensor code comes up. My mechanic of over 2
> years, and the auto shop owner says just because the code comes up
> doesnt mean its the knock sensor that's causing the check engine light
> to come on. I am very frustrated with this whole situation, and
> trying my best not to have the lexus dealer check it out cause it
> could get expensive to check the problem by the dealer. After putting
> the 4th used air flow meter on today the car seems to have more power,
> but the check engine light comes on after about 2 to 10 minutes of
> driving. Something other than the airflow meter is causing the check
> engine light to come on. The code has been cleared over and over
> again. Any suggestions? Thanks.
>
> Michael
>

Mike,

Your mechanic and shop owner are correct when they say that just because a
code for a particular circuit comes up doesn't mean that the sensor in that
particular circuit is bad.

That said, if the code in the computer is pointing to a knock sensor problem
and your guys are swapping air flow meters, I'd take it elsewhere. A knock
sensor is easy to check out, and so is the circuit.
--
Ray O
correct the return address punctuation to reply
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