engine check light 90 200TQ

[John Shuman <shuman@vix.com>]

Hi All,

I have a 90 200TQ with 88K on the clock.  Lately I have had an
unexpaned anomalie with the engine check light.  At 3100rpm, in
3rd, 4th, or 5th gear, the light comes on and stays on even under
full throttle.  I've had the car to the mechanic twice and they 
have checked the mixture and say it is right in. (the engine check
light, according to the mechanic, is to alert lean mixture(?)
Anyway, I haven't notice any difference in power during this display.
I recently added a K&N air filter but, the car was doing this before
and on rainy days it is more pronounced.

Another thing I've noticed, on a hot dry day, (california only right
now :-) ) the car will pop? out the exhaust during high RPM shifts. .
2nd to 3rd & 3rd to 4th only.

TIA,
John
84 5KST
90 200TQ