No CEL. Truck barely runs over 1000rpms

Hey everyone, I have an 2008 Toyota Tacoma 2.7 motor, it’s has been a great truck until a week ago now I can’t wait to take it to the desert and blow it the F**K up.. had an exhaust leak at the flange, barely made it back to my house and popped the hood and melted my o2 sensor plug. Fixed the exhaust leak, changed the up stream o2 sensor(denso) and spark plugs (denso) factory OEM plugs and now it idles like dog crap and dies if it goes over 1000rpms.. thinking of never buying a toyota again. I have expierence with mechanics, but I can’t figure this one out, I’m so frustrated..... if anyone can help please do so.

 

You put it in limp mode. What codes is it giving?

 

No CEL

 

I know it’s in limp mode

 

remove the upstream o2 sensor and see if it runs better with the leak, the cat may be restricted.

 

Okay, I’ll try that. The previous owner said he replaced the CAT about 6 months ago and showed receipts for toyota. So I kinda through that out of the equation

 

There may not be a light but there's got to be a code


For starters I would pull the terminals on the battery, remove the battery from the truck then connect the two teminals together for 10 minutes. Then reinstall the battery and attach the terminals appropriately. This will reset all computers to their basic programming and allows you to start fresh on your trouble shooting.

See if the truck starts and runs with the same issues.

It sounds to me like you may have connected something wrong when doing your plugs and are firing cylinders out of order.

 

My money's on incorrect ignition timing/ firing order...

 

Are you sure the light works? When you first turn the key on it lights up?

Sometime it's the simple things.

 

I drained all the charge from the computer already but nothing changed still the same. And how could the ignition be connected wrong when the length of the harness connects straight into the coil packs????? And all cylinders are firing, it starts and runs with out misfire until over 1000rpms and dies

 

Is there any leaks on the intake tract that you take off to replace the spark plugs

 

Sounds like a restricted exhaust or plugged cat

 

You see there scooter, he thinks of the simplest things first.

 

I drained all the charge from the computer already but nothing changed still the same. And how could the ignition be connected wrong when the length of the harness connects straight into the coil packs????? And all cylinders are firing in order or else the start up would be bad as well right? runs with out misfire until over 1000rpms and dies

 

RPMS Revolutions Per Minute(s)? Lol

Hey Bud I know this is frustrating as all hell and you just want your truck back but it sounds like you need to crack a cold one or two step back from it for a while, relax for a minute before coming back to this one.

Engines are simple creatures, suck squeeze bang blow, they just need air fuel compression and spark, you are missing one, if you're damned sure the spark is good, compression is almost a given, as is air, so it has to be fuel.

If it's dieing when getting to higher RPM and stumbling at idle but not throwing a code then it's probably related to fuel pressure. Look for a small (3/16) vacuum line that should be connected to a round metal project near the rear of your engine on one end and a nipple off the intake tube off the other end. This is the vacuum controlled fuel pressure regulator. It's possible you pulled it off either end when doing your plugs.

 

How did the truck run before you worked on it? Other than the exhaust leak of course.

 

My celica did this. Turned out to be a bad fuel pump. No codes given either

 

Definitely check your cats. That high temp may have melted them. I had it happen in an old 96 Chevy s-10 blazer. I disconnected the exhaust before the cat and she ran like a bat of hell again haha it had the same symptoms tours did though.

 

Have you washed the engine lately or gotten water in the engine compartment?

 

@Key-Rei.. yeah it’s a bit frustrating when people like you say some obvious shit, you think your the joe rogan of Toyota’s.. haha everyone knows how a motor runs, I get it, I’m not looking for a freshman level auto shop teacher..

@Styx586. It was weird, it started running like shit when the exhaust leak started and it progressively got worse until I made it home, I’m leaning towards the cat being clogged. that would make sense, all the back pressure from the bad cat caused the flange bolts to stretch and that’s what caused the exhaust leak to melt my o2 sensor plug. And it hasn’t been able to run good sence the cat conv. was plugged. What do you think?