P0300,p0305,p0306 codes plus flashing check engine light, VSC/trac, and slip indicaor

[SPC4Runnergirl]

I have a 2005 4Runner limited that had been running rough lately then check engine light came on along with the VSC track and the slip indicator light those came on in the past but it had always been a loose gas cap but this time I ran a scanner on it because of how the vehicle had been running I used a fixed scanner and it produced a po306 code misfire cylinder 6 here are the freeze frame data from that date of January 13th when I first ran it.


I decided to let my friend who knows a little bit about cars install a new spark plug just to see if that was the cause of it but he installed a new spark plug in cylinder 5 instead of cylinder 6 because that's where he thought it was so after he was done it wasn't until then that I realized when the code came back up that he installed it in the wrong cylinder but I rescanned the vehicle with a different scanner an actron one and it came back with the same cylinder 6 misfire code along with po305 cylinder 6 misfire and an additional po30 multiple cylinder misfire code so what I am wondering is did he install the spark plug wrong for the cylinder 5 code to come up now being that's what he just replaced I'm just so confused and I don't want him to mess up my car can anyone shed some light also this is the freeze frame data from the actron scan results on February the 2nd the other day when I did it thank you guys y'all are great I love this website

I forgot to add that the check engine light is on and flashing the VSC track light is on and the slip indicator light is on along with those codes.

I'm mainly concerned with why after putting a new spark plug in cylinder 5 (on accident it was supposed to go in number 6) why I'm getting a misfire code for that cylinder now as well as for 6 and now a random multiple misfire code.

 

[SocalSam]

What did the spark plug, coil, and plug well look like? Were they wet or dirty? Inspect #5 coil. Look at boot, coil to spring contact, and plastic housing. Try swapping #1 coil to #5 cylinder.

 

[Buckaroo]

If you drive it for any length of time with the misfire and flashing CEL, you will damage the CAT. On the freeze frame data, the 9.56g/sec MAF reading at idle looks high to me - I would expect it to be around 4.0g/sec. MAF issue would be a multiple cylinder problem. Could try cleaning it or replacing it. Maybe others could comment.

 

[rdruss]

If you drive it for any length of time with the misfire and flashing CEL, you will damage the CAT. On the freeze frame data, the 9.56g/sec MAF reading at idle looks high to me - I would expect it to be around 4.0g/sec. MAF issue would be a multiple cylinder problem. Could try cleaning it or replacing it. Maybe others could comment.

That's a good start. You can really chase your tail on these modern vehicles when they malfunction. I have been watching a youtube diagnostic expert, Ivan, on "Pine Hollow Auto Diagnostics" and the first thing he says is don't start firing the parts cannon immediately until you know why. And if you do fire the parts cannon at least use good ammunition, or in other words, quality parts. He says only use OEM parts if electronic item you are replacing, the knock-offs and look alikes are usually junk and just add to the difficulty in finding the real problem.

 

[Buckaroo]

That's a good start. You can really chase your tail on these modern vehicles when they malfunction. I have been watching a youtube diagnostic expert, Ivan, on "Pine Hollow Auto Diagnostics" and the first thing he says is don't start firing the parts cannon immediately until you know why. And if you do fire the parts cannon at least use good ammunition, or in other words, quality parts. He says only use OEM parts if electronic item you are replacing, the knock-offs and look alikes are usually junk and just add to the difficulty in finding the real problem.

Agree - want to be careful with sensors on a T4R - OEM or OEM supplier only. If the OP decides to replace the MAF sensor, this is the one I would use...
More Information for DENSO 1976030

 

[Buckaroo]

That's a good start. You can really chase your tail on these modern vehicles when they malfunction. I have been watching a youtube diagnostic expert, Ivan, on "Pine Hollow Auto Diagnostics" and the first thing he says is don't start firing the parts cannon immediately until you know why. And if you do fire the parts cannon at least use good ammunition, or in other words, quality parts. He says only use OEM parts if electronic item you are replacing, the knock-offs and look alikes are usually junk and just add to the difficulty in finding the real problem.

Agree - want to be careful with sensors on a T4R - OEM or OEM supplier only. I would first try to clean it but if the OP decides to replace the MAF sensor, this is the one I would use...assuming it's a V6....
More Information for DENSO 1976030

 

[Runnin on E]

I didn't see what engine OP has but why buy a MAF before completing this? This is from the V8 manual. The V6 would be similar.

 

[SPC4Runnergirl]

What did the spark plug, coil, and plug well look like? Were they wet or dirty? Inspect #5 coil. Look at boot, coil to spring contact, and plastic housing. Try swapping #1 coil to #5 cylinder.

Im.not sure I couldn't get much info from my friend. I have. Someone else coming tomorrow to look at it and I will take pics of everything and report back.
I have a v6 limited with over 200,000 miles I forgot to mention

 

[SPC4Runnergirl]

If you drive it for any length of time with the misfire and flashing CEL, you will damage the CAT. On the freeze frame data, the 9.56g/sec MAF reading at idle looks high to me - I would expect it to be around 4.0g/sec. MAF issue would be a multiple cylinder problem. Could try cleaning it or replacing it. Maybe others could comment.

Thank you for your input!

 

[SPC4Runnergirl]

Agree - want to be careful with sensors on a T4R - OEM or OEM supplier only. If the OP decides to replace the MAF sensor, this is the one I would use...
More Information for DENSO 1976030

Thanks will keep this in mind

 

[SPC4Runnergirl]

Agree - want to be careful with sensors on a T4R - OEM or OEM supplier only. If the OP decides to replace the MAF sensor, this is the one I would use...
More Information for DENSO 1976030

I didn't see what engine OP has but why buy a MAF before completing this? This is from the V8 manual. The V6 would be similar.

Thank u..I have a V6

 

[EVAUn1t1]

Any updates on this? Just had my V8 throw all these codes at me today and I am trying not to freak out about what I need to fix.

 

[Ventil8]

I’ve been chasing a P0301 code since mid June. I’ve owned my 2005 V6 Sport 4R since new. I decided to change all plugs, ignition coils, and lastly the fuel injectors….still with rough idle at cold start. So I decided to take pull the coil and look inside the #1 cylinder head. Not good. Oil/coolant in the cylinder. Chat GPT said might be a leaky stem valve. Finally, decided to take it to a Toyota specialist and they confirmed it was a blown head gasket. Small leak causing the coolant to get into cylinder head overnight, rough idle at cold start…runs fine after but get same issue when it sits.

Soooo….having the engine rebuild this week…20.5 years without any issues is pretty good. This was a known issue in early model 4Rs. I’m planning to keep this 4R FOREVER so the price isn’t an issue for me.

Good luck.

 

[Ventil8]

Got the 4R yesterday and drove it to work today. Engine feels smooth and purrs like a kitty. She’s back to normal after the rebuild. Now, need to find replacement tires.

 

[Buckaroo]

What did you pay for the head gasket job and what all did they replace when they were in there?

 

[Ventil8]

An arm and a leg for sure. Labor of course was the most expensive, around $4600. This is the Austin, TX area and had it done at Bearden Automotive, they are Toyota and Lexus specialists.

 

[Richard23]

If it helps anyone.
I’ve been chasing P0300 and Rough starts, since mid December. First items were coils and spark plugs. Ran better but not perfect. Then Cleaned the throttle body, again better but not perfect. I cleaned the MAF and still not perfect. Did some Fuel Trim readings and it led to leak in Intake or MAF. Since I didn’t have any obvious leaks I replaced the MAF and saw a change in fuel readings (after 15min drive). But Co-Pilot said it was a bad MAF (Brand I got from Orielly was misreading already). Replaced with Duralast MAF and readings normalized. 4Runner ran great, good cold starts and hot restarts. But semi hot restarts (fully warm, then shut off for 10-20 min and restart) were still rough. Did more fuel trim readings and it showing bank 2(cyl 2,4,6) has a leaky injector. Waiting on parts to progress, but upon disassembly, found a crack in the PCV breather tube and a clogged PCV Valve.