Get to be new code with that going on. Under the hood inspection!! Rev and listen for the source of the sound if you can. Have someone work the throttle if you need to while listening under the hood.

 

Ok so i went and replaced the intake manifold plenum( plastic) and gaskets now with my scanner im getting high throttle body position sensor readings, and low voltage to maf. Can it be that I need to relearn the throttle body and if so does anyone know the procedure? Thanks

 

the variable intake would cause the car not to start?
on the mazda, its a somewhat common mod to disable it and keep the flaps open.

i think there might be something else going on here.

sounds like a large vacuum leak possibly.

 

Can you post thereadings?

 

Sorry I will post them in a bit but I found its leaking from the exhaust flange connecting header to exhaust pipe, I replaced the worn gasket but still leaking bad, car won't accelerate and soon as u press the gas its super loud leak noise.. what do I do now? I already replaced gasket , did I do it wrong? Or whats going on help please!!!!

Attaching a photo of where the exhaust leak is

 

i know nissan has a TB relearn thats a pain in the butt. Wasnt aware the HL had once.

 

seems like allot of dupes. lol

ive had issues before with excessive exhaust leaks and extreme lack of power. was due to clogged cat.

 

seems like allot of dupes. lol

ive had issues before with excessive exhaust leaks and extreme lack of power. was due to clogged cat.

Yea my fault kept telling me post failed so I kept trying it.. I thought of that too the clogged cat, u know of any quick or simple ways to test that
Thanks

These are some of the readings, at idle, do these mean anything to anyone?

 

a simple way to test the cat is measure the temperature with an IR thermometer.
you could also remove the cat at the front end and look inside with a bore scope.

not going to lie, i dont have the skill set to look at the data and tell you whats wrong.

 

a simple way to test the cat is measure the temperature with an IR thermometer.
you could also remove the cat at the front end and look inside with a bore scope.

not going to lie, i dont have the skill set to look at the data and tell you whats t

Thanks for the tip yeah i dont have the skillset to understand the readings

 

Completelystumped- My 2007 Tacoma 2.7 has similar readings at idle as yours has.
Regarding cat causing back pressure problem, garage can quickly check pressure by inserting pressure gauge in place of A/F sensor. Shouldn't be more than 1-2 psi max underload.

Set your scanner to read MAF/absolute load value/ calculated load value and monitor/record under full engine load(WOT). My MAF reads 70 g/s calc load 97% and absolute load is 85%. This gives an idea of how well engine is breathing under load.

 

Thanks bout ti do that now because im bout ready to throw a match to it and just brun ut in the diveway

Inspection Report

 

See that the LT fuel trims is now at 37% compared to the last post of -3% so there's that.
If total trims LT plus ST is high at idle and decreases as the RPM increases then suspect vacuum leak. If trims stay same or increase positive at higher RPM then suspect MAf or fuel delivery problem.
If you have suspect vacuum leak a smoke test of the intake may be needed especially with that type of intake plenum.

 

Ok so this is what i found with a lil quick trip round the block, @14.194mph/1486.500rpm, LTFT- 6.25% STFT - 18.750%-----
2. @26mph/1340rpm, LTFT- 15.625% STFT- -16.406%..
3** @1885 RPM /22.37mph, LTFT-21. 094%
STFT--, 16.406%
*4. @2340.500rpm/31.07mph. LTFT-37. 500%, STFT-16. 406%.. can you help interpret these reading please. Thanks, keep in mind the car wont go passed 40 mph thats why all readings are under 40 mph, also ima go for s little drive maybe 10/15 minute drive and ill come back and post those reading, i appreciate you helping me out brother.

 

Just to be clear those fuel trims are positive or negative?

 

Sorry about they are positive , theres an exhaust leak and the flange by the 02 sensor upstream, changed gasket abut leak is still present. I read on the scanner on DTC lookup that if there were to be an exhaust leak it can cause these issues, is that true or do you have any idea what else it may be? I appreciate your time to respond btw.

 

Agree definitely repair exhaust leak that close to sensor. If it is B1S2( after the cat) then shouldn't have much effect on the fuel trims. If B1S1( before the cat) then can effect proper operation of the sensor/fuel trims.
Since exhaust leak should be fixed start with that first.
Can't be of much help with the exhaust repair.

Note: Since fuel trims are high positive at idle, its enough to monitor trims while in park.
At this point no need to be driving to get readings.

Let us know how it goes.

 

Thank definitely will try and fix that leak and keep u posted, do u in ur opinion beleive this this to be the cause of my issues with nit accelearating and the following codes?

 

Exhaust leak shouldn't throw off MAF enough to set P0101.
Exhaust leak near the precat O2 sensor can effect the sensor readings.
Is exhaust leak near first O2 sensor?

 

Yes ill post a pic of where it is , its the flange that connects header to exhaust pipe, o2 sensor is right above the leak maybe 3-5 inches .

Its actualy closer than i previously said check out the picture..

 

Question: is the cat converter/sensor original to the engine?

 

Yessir its the original doesnt it look weird as if it dont fit right or line up correctly? U can see the black carbon deposits it leaves when escaping , and as far as i know it is original the only maintenance done on this car since it left the lot has been oil changes (,motor, oil) and break pads, i just now did the spark plugs.. Oil was only changed when they would hear a knock in the engine due to lack of oil, thats why i ended changing the intake manifold plenum entirely and gasket was leaking pretty bad . Car has 200,000 miles. Crazy right? Its my sister's car thats why im trying to fix it for her asap.

 

Ok, with the P0101 and P0171 you can try to determine if MAF is causing the P0171 by monitoring the MAF g/s.
For comparison my Tacoma 2.7 at idle, reads around 3 g/s and increase to around 30g/s at 2000 RPM. If your MAF reading close to this then wouldn't suspect it to be the cause of P0171.
MAF reading around 2g/s or less at idle would cause high positive fuel trims.

If MAF good that leaves fuel delivery as suspect since fuel trims stay high positive at higher RPM.
Note: If trims corrected at high RPM it would indicate vacuum leak.

May be best to have shop check fuel pressure/volume since there is no handy schrader valve in fuel line.
See if you can verify that the sensor in the picture is the after cat sensor. It would be an O2 sensor as compared to the pre cat A/F sensor.

 

Pre- cat

Current readings,
Maf @ idle 2.400 g/s
LTFT @ idle = -2.344%
STFT @ idle. = 3.906%
--------------------------
Maf @ 2000 rpm = 7.140 g/s
LTFT @ 2000 RPM = 1.562%
STFT @ 2000 RPM = 2.344%

 

Looks like running good at least at idle.
If trims stay under 10% thru out engine load then considered normal.
If P0101/P0171 return note the freeze frame data this can help find fault.

 

Well i removed the entire exhaust system feom exhuast manifokld down to the tailpipe, when i stood up the section that conects to eaxhaust manifold it has a acat on it and i stood it upright and chunks of they honey comb fell out and kept falling put, maybe tats the issue u think?

Also yea nunbers are good at idle but car wont accelerate plus what i found coning from cat , im leaning towards new cat

@cj1 what do you think?

 

Well i removed the entire exhaust system feom exhuast manifokld down to the tailpipe, when i stood up the section that conects to eaxhaust manifold it has a acat on it and i stood it upright and chunks of they honey comb fell out and kept falling put, maybe tats the issue u think?

The cat substrate is suppose to be intact and not crumbling. you would need to replace that if its disintegrating

 

the car will run fine without a cat.
BUT, if its THAT bad, those little pieces probably clogged most of the cat.

since the exhaust is off, you probably could take it for one, quick, LOUD, drive around the block to see if the issue is gone.
youll get some O2 codes but thats to be expected.

 

What ever happened?
I’m going through the same issue

thought is was my timing
I replaced the timing chain, the leak on the exhaust
And still the same problem

 

re-read the post directly above.
it was an issue with the catalytic converter deteriorating.

you can also try disconnecting the exhaust and go for a quick drive. see if that solves the issue.
as for replacing timing, why not just look at the timing marks to see if the engine was still in time?