High idle and running rich

[Oppie]

I haven't found anybody near me that will read out the codes (for a stranger
at least) for free. If you have to pay for a diagnostic, it is often worth
it.

What type of maintenance have you done on the car? O2 sensors should be due
and that will make it run rich and sooty. Also check the EGR that it is
closing properly at idle. May need cleaning.

 

[MR]

I have a high idle problem similar to previous poster, but it happens
most of the time....about 50 rpms high and is running rich, consuming
more gas and has the soot around the tail pipe. I have nearly 160k
miles on my 97 SL1 with AT.
Will the code readers at the various auto parts store reveal what is
defective and if so, any suggestions on some parts stores that do this
for a min. chg. or for free.
TIA,
MR

 

[Bob Shuman]

Are you getting a service engine light? If not, there will be no
diagnostic/error code to read. Possible defective CTS sensor telling the
engine it is always cold thereby running it rich?

Bob

 

[MR]

I haven't found anybody near me that will read out the codes (for a stranger
at least) for free. If you have to pay for a diagnostic, it is often worth
it.

Yes, more often than not.

What type of maintenance have you done on the car?

I keep up with regular maint. etc. and try to repair or replace myself
if possible.

O2 sensors should be due

I cleaned that a year or so ago after getting a lite to service eng.
Seemed to do the trick, but may need another.

and that will make it run rich and sooty. Also check the EGR that it is
closing properly at idle. May need cleaning.

Thanks. I'll check it out.
MR

 

[MR]

Are you getting a service engine light? If not, there will be no
diagnostic/error code to read.

No lite, so will rule that out.

Possible defective CTS sensor telling the
engine it is always cold thereby running it rich?

Where is the CTS sensor located?
Thanks,
MR

 

[p_vouers]

driver wheel side towards the to[ center. Under the air tube intake.