P0102 - low signal input from MAF, online diagnostics specifically mention checking electrical connections
p0113 - Intake Air Temp high signal, bad sensor, dirty air filter, and two mentions of checking electrical connections on the sensor
po307 - misfire cylinder 7 (that the rear cylinder on teh driver side). Could be all sorts of things, besides spark. But likely spark.
po351 -
Symptoms
Check Engine Light will illuminate
Engine idles rough
Engine misfires on acceleration
In rare cases, the engine may not exhibit noticeable symptoms
Common Problems That Trigger the P0351 Code
Defective Ignition Coil(s)
Defective Spark Plug(s)
Intake Manifold Vacuum leaks
Carbon buildup in the Throttle Body air passages
Defective Idle Air Control Valve or Electronic Body
po353 - more about defective coil, rest similar to above.
po357 - another squawk about bad coil on #7
po455 - EVAP system large leak. Might be your gas vapor capture cannister, might be a purge valve solenoid / control issue, might be a bad gasket on your gas cap. Might be another corroded / failed line on your chassis, but your guy should have mentioned it to you. You'll fail a smog test in CA with this code. Regardless of your actual emissions readings
It's basically shouting at you about a bad coil on #7 and about potential corrosion issues in your electrical connections. No wonder it stumbles / stutters.
There's lots of OBD codes references and potential solutions on the net, look them up next time. I basically did it here because I've got a near identical vehicle / drivetrain in my driveway. Two, really and one is the same year as yours. So I looked it all up for my own info as much as for yours.
I would swap the #5 and #7 coils, turn the key / energize the system and clear the codes, then start it up. If it is indeed the coil you should then squawk a 0305 code, instead of 0307. And you'll still get all the others 300-series codes as they are all interrelated. That's a 'free' test / method of confirming it is the coil itself, before spending money on a replacement. It shouldn't take more than 20mins to effect this swap. It's 4 bolts and four electrical connections. Rockauto has replacement coils ranging from $20-40ea (USD)
And were I you I'd be getting the undercarriage blasted as clean as possible and get busy coatign everything I could in at least a layer of paint. As for the electrical connections I'd be plugging and unplugging them to reduce any corrosion buildup, blowing out the female connecors with compressed air, maybe sanding the exposed male connectors with something like 600grit+ and then I'd be using a lot of dielectric grease on the connector boots to seal things up as best as possible during reassembly.
I'd be working a lot on maintenance, trying to get back to a 'preventative' state of things, instead of getting hit by unplanned breakdowns / assaults on my wallet. I'd rather invest some time and usually less money, 'fixing' things before they fail, when I can. not to get preachy about it. Just a suggestion.
