Diagnostic Check, What could I have done?

[Talon960]

Was having intermittent horn problems, which I seem to have resolved. Thought I would check the diagnostic codes while working on the car. Went through the procedures and identified several codes with the FI system. However, now the car runs poorly. It ran great before checking the codes, but since identifying them, it's running rough, smoking, etc.

It seems like identifying the codes caused the symptoms to manifest themselves where they weren't before. Is this possible?

Any help appreciated. 1992, 960 Wagon. Thx.

[billofdurham]

Welcome to Matthew's Volvo Site.

Before you checked for codes was the Check Engine Light (CEL) illuminated?

What were the codes?

After you found the codes did you erase them? Sometimes when a code is set there is no real problem with the car, simply a minor hiccough. Erasing the code can put everything back to normal.

Bill.

[Talon960]

Bill,

Thanks for the reply, re: your questions:

Before I checked codes, CEL was on

Codes were: 2-3-1 Lambda Rich/Lean In Part Load Range
2-1-2 Oxygen Senson Signal
3-2-2 Air Flow Meter Hot Wire
3-1-1 Speedometer Signal

Cleared the codes.

Just took it for a test drive and most seems well, through all ranges. Exception, decel after a rev causes RPM to drop below idle, but compensates and is OK. CEL remains off.

Thanks/James