Engine has quit

[2TrunkSteve]

A few days ago I was driving along and I felt a hiccup in the motor. Within another 3 miles it got worse until the car just died. I had it towed home and now it will start and run (poorly) for a few seconds and then sputter out. I used my reader and the codes are as follows:

P0300 Misfire Dmg to Cat
P0301 Misfire Cyl 1 - Cat Damage
P0304 Misfire Cyl 4 - Cat Damage
P1313 Misfire Cyl 1 - Emissions Related
P1316 Misfire Cyl 4 - Emissions Related
P1319 Misfire - Emissions Related

Here's what I am thinking about doing....Any other thoughts before I start ordering parts???

New MAF
Coil Packs
Plugs, Plug Seals and Connectors (I was planning on doing this w/my next
maintenance anyways)
O2 Sensors (all 4)
Fuel Filter (another maintenance planned item)

I was wondering if there is a preventative need to do the AOS as well.

Thoughts?

[stab1991]

Thats what our cars do on the Vipers when the cats go bad.... Over on the VCA sites the discussions are that this can happen after an over-rev. Not sure why but thats what happens with them.

[Topless]

Dig deeper. You still need to find out Why the misfire on cyl 1 & 4. Changing sensors may solve nothing except wallet weight reduction.

Any other codes?
Year, model, mileage?
Recent mods or repairs?
Any other symptoms?

[2TrunkSteve]

It is a 1997 Boxster with 52k miles. It is bone stock except for the GAHH top, desnorkled intake and Pedro motor mount. It has been running great with no issues and I was just driving along at 50 mph when it started hiccuping. I did clean the MAF last year as the check-engine light came on. That was about 6k miles ago.

I have driven it a little more aggressive on a few drives with the local Porsche club, but not hard. I don't believe it's been exposed to any over-revving type conditions.

[BYprodriver]

I would pull the oil sump plate to check for metal etc. in case your IMS bearing is dying & cut open your oil filter too. If everything looks good then I would buy a new set of good sparkplugs & install them while carefully inspecting the old plugs especially cyl. #1 & 4. Swap coils with connecters from #1 & 4 to a different position to see if they are faulty. Then start car & see if it needs anything else. Your AOS will tell you when you need to change it until then don't touch it. A new AOS may be worse than the one you have.

[Frodo]

Originally Posted by BYprodriver

A new AOS may be worse than the one you have.

Why would that be? Just curious...

[BYprodriver]

My original AOS lasted 85K miles the last 2 new AOS I bought lasted 200 miles. If it works it works, if it doesn't work it smokes.