'98 s70: Engine probs, and codes

[drewm]

Hi All, looking for some outside opinions.

I have a '98 s70 with low miles (50k), in good shape, but was rebuilt from a front-end collision.

In general, the car drives well. However every morning, the first attempt to start the car fails: turn the key, crank for 20 seconds, sputters, dies. Second attempt and the car slightly over-revs, but starts right up. It's also been getting poor gas mileage - in the 12 - 15 mpg range.

My code reader (I have the Dyno-Scan for Palm from auterraweb, and though a little pricey I've been super happy with it) pulls the following:

PO305
PO300
PO302
PO304
PO303
PO301
PO455
PO172

Now, the 300-series codes are all mis-fires, in a particular cylinder (that is, PO301 means mis-fire in cylinder 1, PO303 is misfire in cyl 3, PO300 is Random Multiple Misfire).

The PO455 is Evap ECS Leak Detected - which is overly common, and could happen if the gas cap is off.

The PO172 is System Too Rich (Bank 1).

My thought is that whatever is causing the 172 code (System Too Rich) is causing the mis-fires...so I'm ignoring those 300-series codes.

My ordinary thought is that this might be related to the MAS or O2 sensors...but wouldn't they generate codes of their own if they're faulty? Further, on physical inspection they both *look* right.

Given the details, would someone mind chiming in on what they think the most likely causes are here?

Appreciate it.

Regards,
Drew

[Tsquared]

With 50K you might want to do the 60k service which replaces the rotor, distribuator cap, and plug wires a little bit early. With the miss being random I tend to think that it would be an ignition issue or a wiring harness problem.

good luck,

Tsquared