OBD port location 1990 Fleetwood Southwind P30 454

[psa0298]

I have a check engine light that comes on after about 5-10 miles at highway speeds and stays on until the engine is shut off and restarted. This has been happening scince I bought the MH about 5 years ago. I have never noticed any performance issues related to this. The engine did begin to miss under load last year and I have replaced the fuel filter, spark plugs/wires and cap/rotor which seem to have solved the miss. The engine is running very well and I have no complaints but I would like to figure out this check engine light. I have tried to locate the OBD port but have had no luck. I checked under the dash...it must be there but I can't find it. Can anyone tell me where it is located on a 1990 Fleetwood Southwind? Thank you

[Daveinet]

Since it seems to have little effect, I would bet it is the intake air control. The stepper motor gets tired and doesn't move like expected, it will set a code. Check these guys out for cables and software:
http://obdallinone.com/sc/toplevel.asp?cat=2
I'm running TunnerPro, which is a great piece of software, but has a steep learning curve.

[enblethen]

Left side of steering column adjacent to the ECM
Remember it is an OBD 1.

[BluegrassBill]

You may have a OBD I on your coach. If so, It would under the dash to the left of the steering wheel, That's where mine is located. Hope this helps.

[Desert_Captain]

OBD ports started appearing around 1996. Your 1990 might have one but I doubt it. :C