Misfire

I have a 1999 Toyota 4 Runner. I have replaced coils plugs wires injectors o2 sensors and the MAF it still had a slight misfire (2&4)and gas mileage didn’t improve. I’m getting about 200 miles to a tank. now it is blowing back smoke and shaking ALOT The check engine light is not flashing. What are your thoughts and what to try next. Im wondering if I got a bad part or have a bigger issue.
I attached a video of the new issue.

 

Black smoke is an interesting one; how's your oil level?

How'd the plugs look when you pulled them? Specifically 2 and 4?

Did you swap the injectors over to see if your misfire moves along with it?

 

It just got all brand new plugs about 3 weeks ago as Well. We haven’t moved the injectors around yet. That was one of my first thought was a bad part. I’m just not sure where to go from here.

 

Reread what I said; how did the plugs look like?

Since you swapped them out, the old plugs would be in your possession. I always label the cylinder each plug came from and assess afterward.

 

Also I'd hate to think you're having a misfire with no codes.

You sure nothing was saved/stored?

Did you use an OEM MAF as well?

Did you unplug the battery and let it reset after having replaced the MAF?

 

The codes were coming up. I should have worded that better. The CEL is on. Just not flashing line it was before new injectors. The old plugs looked rusted and the ends were black and those were supposed to be only 3 months old but we think the person that did them the first time didn’t actually do them. The codes were cleared with the maf but batter cable was not connected. And yes I’m pretty sure it was an OEM maf.

 

Do a coolant test for exhaust gasses. At least rule that out.

Sounds like maybe a head gasket failure.

-Mike

 

Actually, if it's belching black smoke, that's a rich condition.

You want to swap coils and injectors and see if things move.

It's almost never a bad coil and if you've replaced coil and injectors with cheap Chinese ones, then you have to suspect those now. Cheap Chinese injectors tend to leak like crazy.

Also, are the plugs Denso and are they correct for the car? Prior owner may have changed plugs but of course could have used the wrong ones.

 

negusm is right. Black smoke out the tailpipe means your running rich. Your getting too much fuel. It's also possible it's oil, but if your oil level is correct and not dropping this can be ruled out easily. And it seems like you already changed your spark plugs.

There are only 4 parts that I can see: coils, injectors, plugs, and MAF.

 

So we’ve now try to fuel regulator, as well as O2 sensors. The new O2 sensor for the upstream is reading zero voltage. All the injectors are good We’ve now replace the spark plugs for a third time. What do you think the best way to go from here? It’s check the wiring on the O2 sensor? Get a new O2 sensor? Or what else could possibly be the issue it’s not blowing as much black smoke, but some minor when you floor it me some gas mileage is still at about 100 miles to a tank

 

I don't think an O2 sensor is going to cause a misfire. Still, checking the wiring won't hurt. Check all body to engine grounds too.

If you are misfiring on 2 and 4, I'm not sure what would be common between them.

I'm thinking it's time for a leak down test and a compression test of each cylinder.