2000 s70 idle issues / abs
 

Hi all - I have a 2000 s70 non-turbo; about mid-August ABS failure occurred (CE, brake, ABS, flashing arrow lights came on; no speedometer or odometer; then limp mode home). Had ABS rebuilt by Victor Rocha and car ran as it did before (even a little better), but the flashing arrow and CE light remained on. I used a parts store scanner and found codes (P1113; P1618; P0717; P0722). I cleared the codes and the flashing arrow and CE light went away; but I ran scanner again anyway and found that the P113 (IAT sensor open/short) and P1618 (diagnostic trouble code in another module) codes remained. Been running a few weeks now with no warning lights coming on.

A few months before the ABS failure (and this is my current / remaining issue) the rpms intermittently started dropping to 300 upon starting; sometimes rebounding and holding steady, sometimes stalling. Upon restart it idles okay and I've never had to restart a third time. This usually happens later in the day; never happens first crank in the morning. The idle will also intermittently drop like this while driving when braking, coasting, and/or turning; but rarely results in a stall. The idle issues began happening roughly one month after the alternator was replaced, but not sure if that is connected to problem; or if it is connected to the codes I mentioned earlier. Any ideas as to what to check or clean - and in the most logical order for a novice mechanic - would be appreciated. (I disconnected the MAF as a first step to test that, but didn't notice any significant difference other than the car running a little rougher).