OBD scan tool will not scan 98 jetta 2.0 (bora uk)

[Romb4557]

I have a 98 vw jetta 2liter gas. The check engine light was on and just went out. Now the check engine light will not come on even when the ignition is turned on, also when the scan tool is hooked up it just reads Err. Car is also running really rough with a surging idle. It has new plugs, wires, fuel filter, and MAF. I have also unplugged the computer overnight and plugged back in and the Check engine light still will not illuminate. Im guessing the rough idle and slight misses might be from the EGR valve. Also when ignition is turned on there is a humming sound that seems to be coming from just behind the firewall on the interior side of the firewall that will stop if you disconnect the wiring to the throttle body. I guess its the thottle body it has the throttle connnected to the side of it. The rotor bug and distributor also probably need to be replaced since the prolonged use without changing it has given way to some craters on the post inside the cap. What to do about all these problems.

Thanks,
Will

[Eshrules]

is your jetta a turbo? i was under the impression the EGR only existed on a turbo engine. also, if the engine check light has gone out and not come back on again, be thankful. if it is the same rule as my previous car, once the car has completed a set amount of fault free 'cycles' since the light came on, the light will go out as the ecu determines the fault is no longer present. as for the other faults, i think you're going to need an experienced technician for these, keep your out for RickT/VW techniker. they should help to point you in the right direction....

[Romb4557]

No my jetta is not a turbo so I guess that rules out the egr if only the turbos have it, but Im not positive on that. I thought the check engine light not working anymore might have something to do with the scan tool not reading my car though.

[Romb4557]

I replaced the distributor and rotor bug and the missing problem is cured, but the idle still goes up and down between about 650 and 900 rpm almost in a steady pattern.

[Romb4557]

Anyways, I had checked the cleanliness of the throttle body about a week ago and there was about a paper thin amount of black buildup on the inside right around where the butterfly valve closes and had read somwhere that these throttle bodies operate within a 5 thousandths tolerance, so I cleaned it. It now runs like brand new, although the check engine light is still not coming on when ignition is turned on. I guess the bulb must be burnt out.

WIll