EXH warning light on....

[skrufy]

Hello all-

I just picked up the youngest 911 I've ever owned- a new to me '88 CAB with 46.8k miles on it..... have been doing the usual cleaning/detailing, etc. and chasing some numerous and continuous wiring problems created by some prior owner whose toolbox seems to contain that ultimate finess tool- a chainsaw.....

Anyway, today the "EXH" light came on after idling for a few minutes before doing a test drive. Unless I completely missed it, my NOS owners manual doesn't mention the EXH warning light- nor the Cabriolet warning light for the top when unlocked/unsafe. I know these late 3.2L Motronic FE cars have an altitude module it them. I do live at 8050ft. if that could be a player.

A check of the forums hasn't revealed much.

What trips the EXH light and how can you reset it? Is it an over temp light or a periodic EGR type warning light based on milage to check components, etc.? How critical is the light? Haven't had time to try and find the wiring diagram to chase that circuit down......

As usual, thanks for all the help from the Pelican family.......

Tim

[kidrock]

hmmm, odd....I have an '88 cabby, and I don't have an "EXH" light.

If I were a betting man, I would test the O2 sensor. If the sensor checks out OK, I'd check the air/fuel mixture.

[skrufy]

Kid Rock-

Thanks- will try and do that. I have the wiring diagrams for the 88-89- can't find any mention of a EXH light, nor does my new NOS Owners Manual.....

With the Motronic and it's altitude module, isn't all fuel management automatic?- ie, where to check the fuel air mixture I wonder, if that were the problem, and then what to do about it?

I like your sign off handle, except I thought I was gonna read- "and carry a H&K..."

thanks-

Tim

[schumicat]

I agree it is probably the OXS (oxygen sensor light). it comes on every 30k miles to remind you change the 02 sensor. the counter and light are removed or not working on many cars. it is reset by removing the tach and pushing in a small reset button on the counter unit, which you can see when tach is removed.

[tazzieman]

My Japanese delivered 911 has the EXH light. It would flash from time to time . The car recently had a Japanese spec catalytic converter (from my reading , possibly fitted 2-3 tears after delivery when cats became mandated). I could not find any link between the light and the cat. Maybe the EXH light is a pre O2 sensor way of reminding owners to check the cat.

Anyway ignore it and it will go away. I chased the cat off and put a Euro premuffler in instead!

Where was your 911 delivered? Could it be a grey market Japanese one?

[5495bb]

My Japanese delivery '87 also has a EXH light. It came on when the circuit in the sensor at the exhaust opened. All I did was trace the wires back to the engine compartment and closed the circuit at the connector.

[huba]

Not familiar with Porsche EXH light. but all other makes are triggered by lead from odometer--usually @ 30K miles as in one of the previous posts. Reset is done via a push button somewhere onthe speedo/odo. Good luck.

[skrufy]

Thanks for all the input folks- I really appreciate it. My '88 Cab was built in April 88, and is a US Spec car with the usual EPA/California compliant sticker inside the engine deck lid, and VIN/spec sticker on the driver's door jamb. I have a Letter of Authenticity for it, as well as a recent PCNA LofC, Letter of Compliance, that says it meets all USDOT specs, etc. The LofA states the options, etc. as ordered for delivery, and it also says Calif. DOT/EPA compliant as well. Curiously though, on the inside left of the engine deck lid opposite the US spec EPA/Calif/engine timing sticker mentioned earlier, there is a sticker in what I assume, for no real intelligent reason, is Japanese. The assumption is based on the probability of more people in Japan affording a Porsche vs China.

Today while checking/charging the R12 in the a/c system, the EXH light extinguished, and then came back on after a short test drive to check the a/c under normal driving conditions, and to cool the oil down. Ya got me!

I talked to a mechanic friend of mine today, and he was not familiar with the EXH light either. As an independant Porsche shop keeper, he works on them all- all day.....

I will pull the speedo out tomorrow morning and look for a reset button. I will let everyone know.....
PCNA doesn't have records as to what car went where- ie. which dealership, etc.- at least not that far back. Is there some way to tell if the car was also ready/intended for the Japanese market?

Tim

[tazzieman]

Originally Posted by skrufy

Is there some way to tell if the car was also ready/intended for the Japanese market?

Tim

I've sent you a PM