Need Help ... threw a p1151 code so I replaced the )2 sensor now its showing a p1152

[mccoyxx]

Hey guys ... I recently got a 1996 Explorer Sport 4x4 with a 4.0 in it and it had the check engine light on. I have an Actron OBD2 scanner and hooked it up to see what the problem was. The P1151 said it was a downstream bank 2 sensor. I purchased one from Ebay and changed it and reset the computer and the light went off. The next day it came back on and now it says its a P1152 code. The vehicle has idled pretty rough since I got it and uses gas rediculously. I average around 10mpg ... no exaggeration. I HAVE to get this fixed. It feels so sluggish most times and won't really show any signs of power unless I push it to the floor. Every now and then it will have a small sudden burst of power for just a few seconds then be on its face again. I have noticed that when I am driving ith the cruise control on and press the button that accelerates it that it seems to have very strong power and good response from this. But it doesn't do this wen I use the regular gas pedal ... what is possibly going on here ??????? Thanks for your time in advance ... RSM

 

[mccoyxx]

Oh I also wanted to go ahead and say that I changed my plugs to paltinums ... the wires are in excellent shape and I put a cheapie cold air filter on it from ebay ... just took the intake housing bottom piece off and mounted the filter directly to the end of the intake tube and let it hang ... it isn't pulling on any wires or anything. It did seem to help just a little, but I am still having major issues. The code also did not throw after I done this it was before with the stock airbox and filter still intact ... Thanks again ... RSM

 

[robertoa1a]

It sounds like the engine may be running too rich and may be throwing false codes as a result. Have you cleaned the MAF? Check for vacuum leaks. You may have bad cats but I would look for simple problems first.

Do you have any other symptoms like a sulfur odor or un-burned fuel smell? Does the problem change with temperature? Is there enough fluid in the radiator to reach the Engine temperature sensor.

 

[mccoyxx]

no haven't cleaned the MAF ... could it really make that much of a difference ??? 10 mpg ??? I would have never imagined that .... anyways no I haven't cleaned it or checked for vacuum leaks, but I need to a.s.a.p. ... do u have any tips on how to check vacuum lines ??? this is something I am very unfamiliar with ... and as of the cats ... it seems to be getting good flow from the exhaust and isn't running hot ... so I am thinking its not that. Thanks for the reply ... RSM

 

[Millertime1987]

Do a search for P1151 and the second thread has some info that may help. Sounds like it could be an O2 sensor that is bad.

 

[robertoa1a]

Just my opinion but it sounds like your engine management system thinks it needs twice as much fuel as the engine really needs, hurting performance and fuel econ.

The proper fuel to air mixture isn't being prescribed. That starts at the MAF. It has two elements that heat up inside and when air passes it the resistance is measured which tells the computer how much air is flowing past it. If it thinks there is twice as much air present then it will add fuel.

Now the O2 sensors are seeing a rich fuel to air mixture way beyond the range the computer is designed to compensate for.

Your problem may be something else but I would check the MAF. It may be shot.

 

[mccoyxx]

I see .... ok thanks very much for the fast response ... I will clean and check it and see what I get.

 

[robertoa1a]

I apologize I thought you replaced the O2 sensors and still got a code.

 

[mccoyxx]

I did replace the downstream O2 sensor .... it was giving a P1151 code and after I replaced it and reset the computer the check engine light came back on the next day and gave a P1152 code.

 

[robertoa1a]

Cleaning the MAF is part of regular maintenance any way and doesn't cost much.

 

[muskegolake]

I did replace the downstream O2 sensor .... it was giving a P1151 code and after I replaced it and reset the computer the check engine light came back on the next day and gave a P1152 code.

I believe the P1151 code is the UPSTREAM O2 Sensor. Bank 2, Sensor 1 is the one in front of the cat.

I am throwing the same code and having a ton of low-rpm issues. It idles ratty and, occasionally, it hesitates on acceleration. I went through and cleaned the MAF, changed plugs and changed fuel. The only other thing I can come up with is that O2 sensor...

 

[mccoyxx]

I got the wrong info on the code ??

where I looked it up it said that code was for a downstream sensor. I am believeing it was correct, because afterwards I reset the computer when the sensor behind the converter was changed and it hasn't thrown that code again ? ..... anyways a quick question ... how do you get the MAF sensor off ????? I tried the other day and where the torx bolts have the small stud in the middle I don't have any security bits to remove them ... do I have to buy a special socket ?? I went to NAPA yesterday and they said they don't sell them ... thanks ... RSM

 

[budwich]

odds are other than doing the reset, you have done nothing by changing the downstream sensor as those codes are upstream codes. sometimes they get "going" by contaminated sensors but more likely intake issues. As suggested, cleaning of up stream sensors (MAF) may help.... checking for intake leaks is a good area to focus on.

 

[muskegolake]

where I looked it up it said that code was for a downstream sensor. I am believeing it was correct, because afterwards I reset the computer when the sensor behind the converter was changed and it hasn't thrown that code again ? ..... anyways a quick question ... how do you get the MAF sensor off ????? I tried the other day and where the torx bolts have the small stud in the middle I don't have any security bits to remove them ... do I have to buy a special socket ?? I went to NAPA yesterday and they said they don't sell them ... thanks ... RSM

If you don't have the Torx tool for the screws, I would just remove the entire MAF housing and spray it clean that way. I have a MAC intake on my Mounty so, it is easy to access the MAF sensor without the Torx bit.

 

[robertoa1a]

Take a screw driver and remove the worm clamp from the duct work. There is a external electrical connection that can be easily disconnected so that you can get the whole housing out from under the hood. Now you should be able to sit at a table with it. The mounting plate pops out of the dome shaped housing with a screw driver giving you just enough space to get a 10mm wrench in and remove the two nuts holding the aluminum body to the mounting plate. With the mounting plate out of the way you can work the inside wiring harness off. Look at the two tiny filaments in the ventura. Those need cleaned. I wouldn't touch them with anything if you don't have to.

This is way easier than it sounds taking about 10 minutes.