Doug Thorley Headers Fitment. Show me your ball Flanges.

After nearly 4 months of bullshit my truck is back in my driveway.

I still have some issues to work out like running lean at 15+ LTFT and I need to find a way to make the transmission dipstick work but I didn’t get any noticeable exhaust leaks.

 

awesome news about the exhaust!

 

15 long term is high!
Did you replace your fuel pump, filter and clean injectors?
A bad MAF or dirty or aftermarket will cause high term too

 

Yeah, just hoping the lean issue isn’t anything to do with the exhaust. Now considering a smoke kit because chasing hard to find leaks sucks.

Everything on the intake was touched. New knock sensors, lower intake gaskets, injectors, etc. so it could be anything.

Side note I don’t think Thorley included in the directions. Make sure to tighten the plenum stay BEFORE the driver header. I had to cut that bolt down and getting it in there is not easy.

 

Fuel pump is newish, filter was done not too long ago injectors are the new Densos from motor west.

MAF was cleaned not too long ago. But it’s possible it got contaminated with the air box sitting open for nearly 4 months (hood was down). I doubt that’s the issue but I’m going to clean it anyway. Almost everything has been replaced in the last year or two.

Also, half of tank of gas sat all that time so maybe it’s something to do with that. Who knows. Google says Premium is good for 3-6 months.

Most likely a vacuum leak. But I didn’t have time nor the energy to go looking. Ive been working on this every day after work this week until dark. And didn’t stop tonight until it was ready to crank.

 

Probably important to note that fuel pressure is in spec. So probably not fuel? Not sure how telling that is.

 

You can have a smoke test done for a vacuum leak,
Vacuum leaks are definitely a lean trim ticket

 

Fuel pressure test will not tell you the whole story unless it’s tested and running at high rpms.

I had 15-20 long term trims.

My fuel pump tested perfect at idle but was starving at high rpms because it cut out.
Replaced fuel pump and all was good with long trims at -+ 5

 

I got a smoke kit off Amazon for around $80 I think. Fantastic tool.

Solid note on the plenum stay. Glad mine is still on the stand lol

 

My fuel trims come down with more load RPM. They’re still a little high in the 8 range.

Wouldn’t they stay the same or increase if it was the pump?

Please, for the love of god. Please don’t be the pump. The Double cab has the pump access in the worst possible location forcing you to drop the tank.

 

I pay absolutely no attention to fuel trims, unless it’s bad enough to turn the check engine light on. Even then, it’s only at idle looking for a vacuum leak. It’s going to be different at different rpms and loads. You need an afr meter and pay attention to air/fuel to tune, or check the tune. Long term and short term fuel trims can be misleading, useless information.

 

I did pop a code last night along with bad idling. 26+ on LTFT. I just tightened up the AFR sensor and the intake tube and cleared the code. Now I’m running around 16-18+ with no codes. Something is up.

my fuel trims have always been all over the place. Sometimes 10+ And lower with load and others 0-5 across the board. So what I’m experiencing is a new condition probably due to something that was removed and replaced.

I have had suspicions about the fuel pump. In the past my LTFT would jump higher than normal and filling the tank brought it down. I assumed it was due to head pressure on the pump. I don’t know. Maybe These trucks don’t like aftermarket fuel pumps due to some weird way voltage is handled by the ECU.

I still need to retorque everything on the exhaust and pull the battery cable then see how it runs. Maybe that’ll take care of it.

 

Yeah that’s a horse of a whole different color. I didn’t realize you had a cel on. Most people pay attention to the trims when they don’t need to. Sounds like something isn’t right. Good luck!

 

@1997tacomav6 i think you jinxed me. After work I torqued all the exhaust down again and made sure the intake had no leaks. When I went to go start it just wouldn’t run. I checked the FP gauge and it was zero. I did theirs several times and zero pressure each time. Kicking the tank a few times fixed that.

so I overpaid for a Denso form Autozone and going to install it right now.

I wish I could have gone with a OEM but this is close enough. I think I’m done with aftermarket pumps. This will be my 3rd so far.

 

It ain’t the pump. Quit bitching about a LTFT less than ten. I bet 90% of us are at 12-14 most of the time. Look elsewhere. You just told us nearly the entire engine compartment was molested.

 

I mean, I had a CEL for lean condition. After going over the intake I got it down lower, sure.

But I just got 0 psi and no start after cranking several times. Immediately after a few kicks to the tank I got pressure and it started.

Im not worried about the trims right now. Im more concerned about a fuel pump that’s all the sudden getting stuck.

 

Just an update.

I definitely do have a leak somewhere. I’m able to smell exhaust up front and in the cab in the right conditions.

I think I can hear a tick on the DRIVER side but I’m not 100% sure it’s a leak. All the ticky emissions valves are on that side. Very difficult to pin down.

I guess I’ll just have to wait for soot to appear somewhere or get the exhaust shop to use their experience to track it down.

I know for a fact I have one one after the headers right under the passengers feet. I rigged it up with a clamp until I can get to an exhaust shop for a weld.

Maybe that sound and smell is migrating from under the passenger side to where I’m standing outside the drivers wheel well?

Maybe, but I’ll update after I get back from the exhaust shop and that known leak is fixed

 

You can do a smoke test from the tail pipe pushing to the headers

 

Yeah. Ive looked at a few kits online. Just need to pick one out.

 

Depending on how free flowing your exhaust is, I’m not familiar with your truck, the velocity of the exhaust can have a Venturi effect and pull fresh air in, also contributing to your lean code. That all depends on where the leak is. A smoke tester is probably the best way if you’re by yourself, but another quick way would be to have someone plug the exhaust with a rag or something, just to increase the exhaust back pressure to locate the leak.