Low Idle and Vibration

I'm oddly relieved to see the return of P0302 on the OBD check tonight, along with continued P2445. I think I will switch the coil from 2 to 3 tonight and see what happens when I read the code again tomorrow.

 

Let us know what happens.

 

What is this part? Forgive me, because I'm NOT a trained mechanic and have very little DIY experience, but I'm not afraid to try--so, What is this part? (I'm going to see if my local library has a repair manual tomorrow.)


This is not my photo, but I want to know what this part is. Would it cause the P2441 and P2445 CEL?

As far as swaping a coil after another P0302, I decided to sleep on it last night, but I will probably do it tonight because I cleared the CEL again.

 

That looks like one of your air injection valves. If that is a nipple behind the hose being held, then most likely that little hose with the split needs to be attached to make the air injection valve work like it is supposed to. This could cause that P2441 and P2445 code.

I'm not real familiar with the Tacoma air injection system, but have a Tundra that uses the same technology. I hope they are similar.

 

On my 2008 2.7L there is a hose similar to the one in the picture that runs over the top of my engine. I think I pinched it somehow and since I didn't detach it for my work, I didn't notice that it was out of place. (See, don't freak-check the obvious first! Obviously, I wasn't familiar with my engine compartment, and human error, in this case, is likely.) I also think I've fixed that, so I went ahead and cleared the CEL again. I'm switching COP #2 to #3 tonight and will watch for new CEL.

 

I switched #2 coil to #3 last night, I've had a few trips around town today and so far no CEL has returned. It might go for a while now without a new CEL coming on, but I will let everyone know if it looks like the problems are resolved.

 

Cool, hope it stays that way.

 

Well, the CEL returned today: P0302 and P0300. Looks like the P2441 and P2445 are gone after identifying my human error. I'm wondering why I'm still getting P0302 if I have changed the spark plugs, and switched the coil over plug to another cylinder (and already changed all 4 spark plugs). I did order a replacement coil and it should be here Monday.

 

Just to clarify, you are still getting a miss fire on #2 cylinder?

If yes, could you have a problem with the plug boot?

Old time trick: spray bottle with water(think hair spray bottle) and mist the water near the plug boots. Look for electrical sparking.(arcing). Have truck running and do this in the dark. If you have bad wires or boots, it should show up.

 

Good for older applications, but a COP(coil on plug) has its boot buried deep in the well where the spark plug is installed. Top of COP covers that hole. You might get a light show from up above that's noticeable where the electrical connector attaches to the COP if something is haywire there. I'd pass on that.

I went thru this P0302 thing with an '06 Avalon. Yes - a different model; same issue. The resolution was a new coil. It could be P030x - x = any cyl. After changing plugs, to no avail - a new coil got it done.

 

You think it could be this going bad on me?

$10 BWD Coil On Plug Boot (SPB214)

http://www.amazon.com/BWD-Coil-Plug-Boot-SPB214/dp/B00V7AZOWQ/ref=sr_1_1?s=automotive&ie=UTF8&qid=1462765761&vehicle=2008-76-1037-20-103-53-9-8-7874--8-1-2642--1-0&sr=1-1&ymm=2008:toyota:tacoma&keywords=spark+plug+connector+boot

I did inspect the bottoms of the COPs before I replaced them into each cylinder, and again when I switched #2 to #3. There didn't seem to be anything obviously cracked or dirty. I will look again, though, and also compare to the new coil when it arrives.

 

So, I did put a new coil into cylinder 2 and it's still throwing a P0302. I don't think my original coil OR PLUGS were bad. So if it's not the plugs and not the coil, I should probably test for a bad injector, right? Is it often that fuel injectors go bad and need replacing?

 

No, not often at all.

It does happen, but it usually happens during the first few hundred miles not years down the road. I would get a compression and leak down test to see if there is an issue with the head gasket.

 

On second thought I do think maybe 1 coil was bad because when I switched it I got the P0300 and the P0302 codes. And, the gaps of the original Denso plugs were all over the place between the 4. I am probably going to take it back in to Toyota to see what they say, now. Their original recommendation was if CEL comes back to change spark plugs and coil. Well, I've done that and the same cylinder is an issue. I least I didn't pay them for this part of the testing/diagnostics and parts replacement.

Thanks for your input.

 

Read thru this whole thread if you haven't already:

https://www.tacomaworld.com/threads/engine-code-p0304-cylinder-4-misfire.242387/

 

In case anyone happens upon this thread...I know it's been a while but I would like to report what the issue was: Turns out that I had a clogged injector and my mechanic said it needed flushing to clear it out. I assume whatever they did was correct because my truck is back to its ole self, power regained, no CEL or detectable misfire. I'm glad it wasn't the head gasket as I feared, though I wonder if I could have "flushed" it myself, now.

Thanks!

 

Thanks for the update.

Its great when things turn out way better than we expected.

 

I've established that my head gasket is fine. I might need to get my injectors checked!

Thanks for the update.

 

I'm bumping an old thread, but if it helps one person it might be worth it.

I took my truck in to have the timing cover leak looked at. When I got it back I saw on the paperwork that they resealed the front sub oil pan. I called the mechanic (super nice guy) and asked about the oil pan and pickup being replaced. He said the pickup had a decent amount of sludge on it so he just decided to replace it while he was in there which makes perfect sense to do.

My hesitation on cold acceleration is basically gone, and my idle is much better now. I asked if he thinks we should have pulled the valve covers and checked all that, but he said it was probably fine and most of the sludge was probably just in the bottom of the pan since I had 196k miles.

So if your truck has a low idle, might be an inexpensive thing to check.

 

SOLVED - I discovered this issue in August 2021, I have been reading these threads forever trying to fix the issue. Cleaned the throttle body, it didn't hurt. What actually helped with my 2013 Tacoma 4.0 was the Mass Air Flow Sensor.

$86 Denso 197-6030 Mass Air Flow Sensor

Denso 197-6030. Purchase the dense one, it works well with Tacoma OEM parts. Good luck everyone. found one on Amazon for $60, amazon said it didn't fit my model vehicle but it does!