Service Engine Soon 00 D2 with 90k miles

[LisaB]

2 months ago I replaced plugs with Bosch Plat 4's at 73k. Ran smooth.
1 month ago an intermittent miss started. Got worse, but fuel mileage improved.
1 month ago the SAI pump began running on it's own, with the engine off and the key out of the ignition! This eventually stopped on its own.
Now SAI is rumbling while running when first started, like a fan is out of balance or a bearing is bad. At least it goes off now.
Service Engine Soon light came on this morning on the way home from work. I bought an Actron 9125 code reader (wow, cool!) and got the following codes:
P1590 Yeah, the ABS/TC/Hill Decent problem. Ignoring this one for now.
P0302 #2 Misfire
P0300 Multiple misfires

MIL On
IM Monitors:
0 Inc
Misfire
Fuel
Comp
Catlyst
Evap
Sec Air
O2 Snsor
O2 Htr
Oh, where do I begin? I think I will try the spark plug wires first. Should have changed them when I did the plugs.
Next, the O2 sensors, they were due at around 60k anyway.
The SAI pump, my local dealer wants $279.62 US.
Possible air (vacuum) leak?
Dirty fuel injectors? Bad Cats?
Has anyone else been through this? Am I on the right track?
Thanks all,
L.

 

[joey]

Start by removing the Bosch plugs, and install the cheap champions that LR recommends... see if issue goes away. If it does, great. If not then we can go on.

Cats can be tested for free at most muffler shops.

O2 sensors will cause fuel economy to drop when they go bad.

Wires could be the issue, if your changing them, get some good ones... (magnacore 7 or 8 mm) 100% better than LR ones and cheaper.

 

[LisaB]

While waiting for the Magnecors to be delivered I will do the Seafoam green decarbon treatment. I used to have to do this to my 85 Scrambler, so I am familiar with it. I also want to clean the injectors via the way shown on the DIY network:
http://www.diynetwork.com/diy/ab_auto_fuel_system/article/0,2021,DIY_13679_2276265,00.html
Then I will change the oil, reset the codes, and drive it. That may fix some but not all of the problems, but there are so many I have to fix them in stages.
Looking back at my records, I did install the Champions, not the Bosch plugs.
Will keep y'all updated, thanks for the advice.
L.

 

[LisaB]

Here's an update:
Started removing stuff to replace the wires, realized I may as well remove and clean the injectors while I was at it.
Found a shop that bench cleans injectors. Took mine in, his machine would not do them because they are the small bodied ones. The best he could do was an ultrasonic cleaning, where they are in a cleaner bath and energized to move the actuator or whatever it is called. The cleaner is not under pressure, so I thought what's the point. He wanted $20 each no warranty.
So I left with my injectors, deciding to clean them myself. I found a repair injector harness at BAP (part #920180B FIS) and I plan to get a momentary rocker switch, lantern battery, a **** sprayer and use seafoam to clean the injectors. I don't have time to do the fancy JectoRate deal, but it looks neat.
I couldn't believe the stuff I had to remove to get the injectors off. Guys, there is no way you can replace the plug wires on a 2000+ D2 without removing the upper plenum. a 1999 maybe, I don't know. I sure hope I remember how it all goes back together.