2001 Toyota Sequoia P0174

[Tlhfirelion]

223,000 miles, V8. I've had this CEL/code pop up and then disappear a few times for the past couple months. Ive had the code run at the auto parts store and they said it was one of my O2 sensors but they don't know which of the 4 it is. I've tested all the sensor heating elements with my multimeter and they always check out. The truck always seems to run just fine, no change in MPG's. I've looked for any vacuum leaks but found nothing. I'm not sure what exactly is the issue and why it keeps coming and going. I've been so busy I haven't had the time to drop it off at the mechanic.

Anyone have any idea what else I can check or ever experienced this before?

 

[THafeez]

Happens to the car in my sig too. In my case its bank 1 sensor 2 the AFR sensor. It comes and goes sometimes during extremely cold days or from bad gas IMO. I've been getting top tier BP regular for the past 5k since gas has been cheap and it hasn't come back. I also put a bottle of techron in every 2-3k. I don't know if makes difference, but thats what I do and it works for me. I checked the voltage and looked at the OBD data for the sensor. Everything was in line with OEM values so I'm not gonna touch it. Unless I see a huge drop in MPGs I'm not spending 100 dollars to change it.

 

[goodtimes]

Check the large rubber air intake hoses from the air cleaner to the air box and throttle body if it has them. They are 15 years old and they do get cracks from changing air filter etc. The code doesn't mean the o2 sensor is bad like the auto stores like to say.

 

[Trav]

You need to look at the fuel trims, that information will help pinpoint the issue. Do not start swapping parts.

 

[Tlhfirelion]

and how would I go about doing that?

 

[Tlhfirelion]

Interesting, I will check those hoses.

 

[Tlhfirelion]

I meant how would I go about checking the fuel trim. I wasn't specific enough on my last reply. Merry Christmas to everyone.

 

[Trav]

You need a scan tool that reads real time data. You can either buy one that will serve most DIY well for years or have a garage scan it. Keep in mind some garages charge $75-100 one time and if you want to verify the repair you just spent the p[rice of a tool and have nothing to show for it.
Once you know the trims someone here will properly interpret the result and point you in the right direction for a successful repair.

I have a pro scanner but also a 31703 for quick work and it works fine, I rarely need to get the more advanced unit out unless I need its more advanced manufacturer specific modes and bi-direction tools. The 31603 is cheaper and only missing OBD I it has otherwise all the same functions. It will pay for itself the first job.

https://www.amazon.com/Innova-31603-CarS...ds=Innova+31603

http://pro.innova.com/Product/FullDetail/b8e56409-4cbb-4455-9e86-cdbdc3a5d545

 

[Tlhfirelion]

Ok fellas, so an update on this issue. I FINALLY got it over to my mechanic (work and being sick cost me a few weeks) to use his high end scan equipment to see whats going on. His notes were this.

"Lean condition on B1 and B2 and GPS on MAF are at 6.80 at 700 RPM's. GPS should be around 4.0 to 5.0 GPS at idle or 700 RPM's. Clean MAF and test drove vehicle. Seems good at this time but will probably need MAPS replaced. Currently operating at 4.86 GPS now".

I had this checked 2 days ago. On my way to work this morning I noticed I was averaging about 2.5 MPG's better than I ever have. Then, as I was turning into work the check engine light came on but as before, the vehicle seems to be running fine. I ran my little code reader right after I parked and it's the same codes as before.

More random info. I did clean the MAF this past summer with the correct spray but it didn't seem to help anything so maybe it's going bad? I do not know if it is the original sensor or not but it does say "TOYOTA" on it so it may be the same sensor with 225,000 miles on it. I can order a sensor online at Rockauto for 60-70 bucks and they're easy to install.

So my plan is to order a new sensor and install that. What does the hive here think about my plan after the most current information?

Thank you in advance for your assistance.

 

[Vikas]

Are you sure it is only 60-70? For MAF, you always want an OEM or equivalent sensor.

 

[Tlhfirelion]

http://www.cardone.com/Products/Product-...413&jsn=413

78 bucks.

 

[Tlhfirelion]

if that won't work please let me know. It seems to be what is needed.

 

[Vikas]

I will let somebody else tell you how bad Cardone products usually are. Try to find an online Toyota dealer and their price on the original one. At least see if the part is made by Denso or Hitachi and then see if you can find it cheaper elsewhere under the manufacturers name.

Look at the numbers printed on your MAF and then enter it in the Google and see what comes up.

 

[Trav]

It seems to be a verified MAF issue so for the price of this one its worth a shot after so many miles. Forget the Cardone go Hitachi for $61 with free shipping or even cheaper at Rock but the shipping might cost more. BTW Hitachi is the OE manufacturer for this one.
Quote:
HITACHI MAF0048 Sensor Only Actual OE Part; part supplied without metal cover


https://www.amazon.com/Hitachi-MAF0048-Mass-Flow-Sensor/dp/B004SJS8YY

 

[Tlhfirelion]

Originally Posted By: Trav
It seems to be a verified MAF issue so for the price of this one its worth a shot after so many miles. Forget the Cardone go Hitachi for $61 with free shipping or even cheaper at Rock but the shipping might cost more. BTW Hitachi is the OE manufacturer for this one.
Quote:
HITACHI MAF0048 Sensor Only Actual OE Part; part supplied without metal cover


https://www.amazon.com/Hitachi-MAF0048-Mass-Flow-Sensor/dp/B004SJS8YY


Thanks for the info and the link. The price turned out to be exactly the same for the hitachi on amazon as on rock auto. It's been ordered.

As always thanks for the assistance. Great site!