'97 4Runner with multiple error codes

[MOR317]

Hi folks,

I bought my 1997 Toyota 4Runner Limited last July and within the last two months I have received some startling error codes. It currently has about 295,000km (approximately 183,300mi) on the engine, if that matters any. I have consulted a couple of "backyard mechanics" (one is a jet engine mechanic, the other is currently transfering from the infantry to vehicle technician in the military) who advised starting with changing the spark plugs. Pay day is coming up so that will get taken care of, but I thought I would post here and see if I could get any wisdom on what other issues may have caused the codes.

I own a MaxiScan MS309 OBDII/EOBD code reader and had seven codes displayed. They are.......
P0300 - Random/Multiple Cylinder Misfire (displayed twice)
P0301 - Cylinder 1 Misfire
P0302 - Cylinder 2 Misfire (displayed twice)
P0306 - Cylinder 6 Misfire (displayed twice)

The effect since receiving the error codes are: Vehicle idles rough, hesitation when accelerating from a stop, decreased fuel economy/increased fuel consumption, and a clunking/backfire sound in the engine bay when hard accelerating.

Also, my brake resevoir seems to not want to hold brake fluid. In a recent trip from Brandon home to Winnipeg (approximately 200km or 125mi) I had no issues on the highway as I rarely used my brakes. Only when I arrived in the city did I have any issues. The brakes still work and fluid remains in the half of the resevoir closest the the cabin. This is another item my mechanic friend will take a look at, but again, thought I'd gain some perspective.

Any help is greately appreciated. Thanks!

 

[Acidmeld]

Definitely sounds like plugs...

 

[mojo34]

Sounds like you just need a good tune up and some general maintenance.

You might have brake line starting to rust through, or maybe a rear brake cylinder leaking.

 

[MOR317]

So I thought I would update this a little: I changed the spark plugs, opting to go with the NGK Iridium plugs as suggested by many users on the forums. The lost power in the engine has been restored, and briefly there were no error codes.

Key word - briefly.

I have since registered a misfire on the #1 and #6 cylinders, and am now having to explore replacing the coil pack. Any suggestions as to what I should be checking next if this doesn't correct the issue?

On an unrelated note, due to a motor vehicle collision about two weeks ago, I'm also getting my grill and front bumper/headlight assembly replaced! Thankfully no one was injured, but there is now more damage on my license than anything. I've got a few pics, I'll have to post them at some point and post up some post-repair pics afterwards. The repair work is being done by a Toyota dealership, so hopefully if I've got the spare coin kicking around at the time of repair I'll get that tune up.

 

[MOR317]

Just a bit of an update - my mechanic has a coworker who described receiving the same misfire signal when he changed his stock (OEM) plugs for non-OEM.

Has anyone found this to have happened?

 

[mojo34]

Don't know if I've ever heard of this, but I'm not a mechanic...unless you have a couple wires touching/crossing each other.

 

[MOR317]

I'll have to look into the wiring. I'm not a mechanic either, the closest I got trained for was basic vehicle maintenance. Anything beyond the basics we passed the vehicle on to the V-Techs as it was their jobs to know the vehicles inside and out.

The only other issue I'm currently working on is the idle noise. Currently it sort of "chugs" and is overly loud. I imagine this is something that the tune-up may be able to correct and that'll happen when the truck goes in for its body work.