1999 Toyota 4runner Has no Power Codes p0171 p0100 p0110

[randomgnarkill]

Hi, Im new to this forum and have been reading tons of posts.
I need help I just bought a 1999 Toyota 2wd 3.4l 4runner with 195000mi and it has a problem with power.
It wont gain any speed at start maybe 20mph and If I press the gas down it gets slower. I have built it up to about 65mph downhill but with slow gas pedal pressure. The Check Engine Light came on so I went to AUTOZONE and got these codes p0171 p0100 p0110.
Then after I reset the 4runner the Check Engine Light went away but the problem stayed
Mostly about MAF. p0171 p0100 p0110
I cleaned the MAF and Throttle. I also just changed the Fuel Filter because it was only $18.
What do you guys think?
THanks James

 

[Buckaroo]

The P0100 and P0110 codes are pointing to a MAF wiring harness issue. First steps - Inspect visible wiring to MAF for damage. If none, unplug MAF wiring harness connector and inspect both the male pins and the female receptacles for damage - on the female side, the receptacles can get opened up if too large of a probe has been inserted in the past. If no damage, reattach connector, clear codes and see if issue has been resolved.

Buckaroo

 

[randomgnarkill]

The P0100 and P0110 codes are pointing to a MAF wiring harness issue. First steps - Inspect visible wiring to MAF for damage. If none, unplug MAF wiring harness connector and inspect both the male pins and the female receptacles for damage - on the female side, the receptacles can get opened up if too large of a probe has been inserted in the past. If no damage, reattach connector, clear codes and see if issue has been resolved.

Buckaroo

they looked OK. should disconnect the wire harness at the manifold also?
they all seemed opened the same. ill attach pictures asap

 

[Buckaroo]

When you get a P0100 or P0110 code, the ECM goes into fail safe or limp mode and locks in certain engine operating parameters because it can't depend on the sensor input. You need to fix these codes or the truck will not run normally. Some info from FSM attached on fail safe mode.

I would suggest ignoring the P0171 for now and concentrating on the P0100 & P0110. Detail from FSM on addressing these codes attached.

Buckaroo

 

[Buckaroo]

Missed the info on P0110 - attached here.......

 

[randomgnarkill]

so would this be as simple as just replacing the MAF sensor or something alike. or would be much more harder in terms.
Can a small Voltage battery be the problem?
I dont have a Toyota Tester.

 

[Buckaroo]

Yes, I suppose that replacing the MAF could fix it. As I look over the Diagnostic decision tree for P0100, I see that it indicates that, given the test results, the MAF should be replaced at several different points. No so, however, for P0110 - that DTC seems to point directly at an open or short somewhere in the wiring harness. Given the info currently available, I think replacing the MAF would be a shot in the dark given and it is not cheap.....$73.79 from Rockauto plus delivery for new Denso MAF. This is not rocket science but, to determine where you problem is and avoid expensive guessing, you need help from someone who has a voltmeter and knows how to use it. It would be easier to follow the test sequence if you had a tool that gave you access to the data points like the Toyota Tester but most often it is not required. Maybe others on the Forum have ideas.

Buckaroo

 

[randomgnarkill]

Yes, I suppose that replacing the MAF could fix it. As I look over the Diagnostic decision tree for P0100, I see that it indicates that, given the test results, the MAF should be replaced at several different points. No so, however, for P0110 - that DTC seems to point directly at an open or short somewhere in the wiring harness. Given the info currently available, I think replacing the MAF would be a shot in the dark given and it is not cheap.....$73.79 from Rockauto plus delivery for new Denso MAF. This is not rocket science but, to determine where you problem is and avoid expensive guessing, you need help from someone who has a voltmeter and knows how to use it. It would be easier to follow the test sequence if you had a tool that gave you access to the data points like the Toyota Tester but most often it is not required. Maybe others on the Forum have ideas.

Buckaroo

It didnt have the check engine light on then it came on. I ran the codes and reset it and the check engine went away but not the problem.
thanks i think one of my friends worked from a toyota place maybe he has a toyota tester. THanks

 

[randomgnarkill]

Yes, I suppose that replacing the MAF could fix it. As I look over the Diagnostic decision tree for P0100, I see that it indicates that, given the test results, the MAF should be replaced at several different points. No so, however, for P0110 - that DTC seems to point directly at an open or short somewhere in the wiring harness. Given the info currently available, I think replacing the MAF would be a shot in the dark given and it is not cheap.....$73.79 from Rockauto plus delivery for new Denso MAF. This is not rocket science but, to determine where you problem is and avoid expensive guessing, you need help from someone who has a voltmeter and knows how to use it. It would be easier to follow the test sequence if you had a tool that gave you access to the data points like the Toyota Tester but most often it is not required. Maybe others on the Forum have ideas.

Buckaroo

how would you replace the wire harness?