John Veninger

Does anyone have information on difference in emissions component on an S4 which was delivered to California verses other states (c02 vs. c03 option code)? I can't seem to find any written documentation.

borland

I have a 90', without the "check engine" bulb installed by the factory.....

When I replaced the burnt bulbs on my instrument cluster, I noticed that there was a slot for the check engine bulb and the check engine icon is present in the display.

Since then, I've wondered if the functionality is built into the instrument cluster's computer to be able to recall engine trouble codes with the lamps blinking function as described in the WSM.

Has anyone has installed a bulb there on a 90', in order to take advantage of the diagnostic function of this lamp?

borland
90' S4, Slate Metallic

Vilhuer

Isn't there small difference between C03 and others where air pump control valve gets it's vacuum at throttle body?

John Veninger

Erkka,

That's what I'm looking for. Any documentation?

Does anyone with a C03 have a check engine dash? Especially an earlier S4's.

Rich9928p

It is my understanding that as of the S4 all cars were designed to pass CA emissions. While the cars themselves may not have been certified, there is no difference in the fuel LH injection and EZK spark controller code for CA and non-CA cars.

John Veninger

Thanks Rich, but why a C02 and C03 option code? Maybe to make California happy?

Rich9928p

Good questions, I do not know the answer to that question. It may be a paperwork issue.

Vilhuer

John,

See Service Info Tech 1987 page 1-14. California cars get vacuum maybe 1/2" closer to throttle flap than 49 state version. Not sure what it does to air pump control. Perhaps rpm when air is directed to filter housing instead of catalytic converters is little higher or lower.

John Veninger

Thanks Erkka!!