P0171 and P0141 codes on but previous owner put on new MAF sensor

[californium90]

Hey Guys, so I just picked up my ride last week on wednesday. When I test drove it there were no CEL lights or any of that thing happening. I took it to work 75 miles one way and still good on the way back, it popped up a CEL and I took it to Advance Auto Parts for a diagnostic check, turns out it popped a P0171 and P0141 code. I did quiet a bit of reading and research online, took the MAF sensor out and cleaned it with CRC MAF Sensor cleaner. When I took it out, I realized that it was aftermarket and the previous owner must have just put it in as there was no grime or dust on it and it looked brand spanking new. So now, the question that I have for all of you is, Do I go buy another MAF sensor from Advance Autoparts or change the O2 Senors? Its showing a Lean code and a bank sensor code. The Vehicle has 220K mile on it and I need to have it NY state inspected and it wont pass inspection with a CEL on. Any input will be appreciated. Thank You!

 

[californium90]

Guys any help on this will be appreciated.

 

[kball]

p0141 is pointing to the rear O2 sensor. p0171 is normally the MAF, vacuum leaks or the front O2 sensor. IF neither O2 has been changed I would do both to set a baseline and fix the 141 code and possibly fix the 171. If the 171 is still there then maybe it doesn't like the aftermarket MAF or there's a vacuum leak. I don't remember offhand if people have had issues with aftermarket MAFs or not.

 

[Rock_Rat]

Do I go buy another MAF sensor from Advance Autoparts or change the O2 Senors?

You need to pick up a new OEM MAF sensor first. Don't go aftermarket on your sensors. That's for the 0171 code (lean). Also you may need to change your PCV or check your hose to the PCV.

The 0141 code is for the heater circuit on the rear O2 sensor. Crawl underneath and check your connector first. You may have a wire that's pulled out or broken.

Start with the easy stuff first. The 0171 code is a "Fail Safe" code. You'll be OK temporarily.

 

[californium90]

You need to pick up a new OEM MAF sensor first. Don't go aftermarket on your sensors. That's for the 0171 code (lean). Also you may need to change your PCV or check your hose to the PCV.

The 0141 code is for the heater circuit on the rear O2 sensor. Crawl underneath and check your connector first. You may have a wire that's pulled out or broken.

Start with the easy stuff first. The 0171 code is a "Fail Safe" code. You'll be OK temporarily.

Where would you recommend I go for my OEm sensors besides the dealer who will Rape me? Also, I have been trying to research the part numbers for the OEM O2 Sensors, but there are so many options.

 

[gamefreakgc]

Where would you recommend I go for my OEm sensors besides the dealer who will Rape me? Also, I have been trying to research the part numbers for the OEM O2 Sensors, but there are so many options.

Amazon actually isn't a bad place, but don't always trust the "This fits/doesn't fit your 4Runner" in the corner. If you can find the part number off a Toyota parts site search Amazon for it.

 

[TheDurk]

Amazon actually isn't a bad place, but don't always trust the "This fits/doesn't fit your 4Runner" in the corner. If you can find the part number off a Toyota parts site search Amazon for it.

What you need is the DENSO part number, not the TOYOTA part number. Then search Amazon for that. Two good sources:

Oxygen / AFR Sensors - Underdog Racing Development

Find My Part | DENSO Auto Parts

You don't give your year or engine, but this MAF works on the '99+ V6 and can be adapted to the older ones if you score a junkyard airbox. Like [MENTION=115347]gamefreakgc[/MENTION] said, ignore the "It does not fit" from Amazon, read the reviews from 4Runner owners.

https://www.amazon.com/Denso-197-6020-Mass-Flow-Sensor/dp/B004J398Y8/ref=cm_cr_arp_d_product_top?ie=UTF8

 

[californium90]

What you need is the DENSO part number, not the TOYOTA part number. Then search Amazon for that. Two good sources:

Oxygen / AFR Sensors - Underdog Racing Development

Find My Part | DENSO Auto Parts

You don't give your year or engine, but this MAF works on the '99+ V6 and can be adapted to the older ones if you score a junkyard airbox. Like [MENTION=115347]gamefreakgc[/MENTION] said, ignore the "It does not fit" from Amazon, read the reviews from 4Runner owners.

https://www.amazon.com/Denso-197-6020-Mass-Flow-Sensor/dp/B004J398Y8/ref=cm_cr_arp_d_product_top?ie=UTF8

Thank You for pointing me in the right direction for the MAF and the denso parts, I did a search for the O2 Sensors and to my understanding, the Calif Exl. O2 sensors are the same upstream and downstream, am I correct? There are so many possible available parts that its driving me crazy. Its a 1999 4wd limited.

 

[TheDurk]

Thank You for pointing me in the right direction for the MAF and the denso parts, I did a search for the O2 Sensors and to my understanding, the Calif Exl. O2 sensors are the same upstream and downstream, am I correct? There are so many possible available parts that its driving me crazy. Its a 1999 4wd limited.

Yes. 234-4162.