Need oxygen sensor help p1151 code

Hey ppl. I recently came into a 1996 explorer sport 4x4 with a 4.0 in it and it is terrible !! terrible !! on gas mileage. The plug wires appear to be in excellent shape and I have taken the plugs out also and replaced with new ones. It took some of the miss out and now it runs about 85%-90% smooth but it has very weak power and I have gotten around ... you ready ? 74 miles on almost a half a tank of gas ... I can't drive it and it guzzling this much !! the check engine light is on, so I hooked up an Actron OBD code scanner and received a p1151 .... I read online and it says the p1151 code is an oxygen sensor code that is bank 2 .... to the best of my knowledge this is the sensor behind the converter correct ? .... I purchased an NGK downstream converter .... I am pretty much just asking if this is the correct sensor for the p1151 code and also some pointers on the easiest way to change these properly without a wrench specially made for O2 sensors ... thanks in advance for your time .... RSM

If your worried about buy the wrench you can go to autozone and rent the wrench that what I'm doing today.

mccoyxx said:

Hey ppl. I recently came into a 1996 explorer sport 4x4 with a 4.0 in it and it is terrible !! terrible !! on gas mileage. The plug wires appear to be in excellent shape and I have taken the plugs out also and replaced with new ones. It took some of the miss out and now it runs about 85%-90% smooth but it has very weak power and I have gotten around ... you ready ? 74 miles on almost a half a tank of gas ... I can't drive it and it guzzling this much !! the check engine light is on, so I hooked up an Actron OBD code scanner and received a p1151 .... I read online and it says the p1151 code is an oxygen sensor code that is bank 2 .... to the best of my knowledge this is the sensor behind the converter correct ? .... I purchased an NGK downstream converter .... I am pretty much just asking if this is the correct sensor for the p1151 code and also some pointers on the easiest way to change these properly without a wrench specially made for O2 sensors ... thanks in advance for your time .... RSM

Click to expand...

P1151 is "Bank 2, Sensor 1." That is the Drivers Side in FRONT of the CAT. You really should invest in the socket to get the O2 sensor out. They are not expensive and well worth avoiding rounding off the bolt.

If it's rusty you better get the special socket.

The last one I changed came out so hard that I ended up having to heat the pipe cherry red to get it to turn.

no O2 switching

P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2

The PCM is constantly looking for O2 sensor outputs crossing 0.45 volts. Rich is O2 output greater than 0.45 volts and lean is O2 output less than 0.45 volts. If there are more than 60 seconds since the last switch while in closed loop then a DTC gets set. In your case the PCM is not seeing the rich condition when it should. It will attempt to force the switch by increasing the short term fuel trim (STFT). When the STFT is at its limit and the PCM doesn't see a switch within 30 seconds after the last switch while in closed loop a DTC gets set. The result is that the PCM is making your vehicle run rich which impacts fuel economy and performance. It can also shorten the life of your catalytic converter since it's temperature will increase.

The PCM also runs a O2 response rate test once per driving cycle. It produces a 1.5 hertz square wave fuel control routine. Since you're not getting DTC P0153, your O2 sensor output is following the waveform and it's output exceeds 0.5 volts.

Since you're not getting DTC P0174, Bank 2 too lean, the long term fuel trim (LTFT) with STFT are within limits.

I guess I agree that replacing the O2 sensor is the logical step after making sure it's vent to outside air is not plugged and the electrical connection is good. It's probably not worth the aggravation to swap Bank 1 and 2 sensors to see if the problem moves.

If you use antiseize compound when you install the new sensor it will make future replacement easier.

OK you may as well have spoken a foreign language as I am wayyyy not that smart

But however ... thanks for the response ... so you are thinking I should change another oxygen sensor ? ... I already replaced the downstream one and reset the computer and the light went away ... drove it to town and back and the check engine light came back on ... scanned it again ... now its giving a P1152 code .... seems to be running the same as before though with no noticeable changes whatsoever .... replaced the plugs with platinums and put a cold air filter from ebay and put synthetic oil in ... getting roughly 14 mpg now ... a lot better than the < 10 when I first got it .... anyways ... so could this still be an oxygen sensor even though P1152 is not a sensor code now ? ... thanks ... RSM

Wrong sensor

P1152 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank No. 2

As muskegolake pointed in a previous post, P1151 applies to the upstream (pre-catalytic converter) sensor not the downstream (post-cat) sensor. You replaced the downstream sensor. You are still getting codes associated with the upstream sensor (went from lean to rich). After you clear the memory, it takes two driving cycles before the CEL illuminates but the code gets set on the first drive cycle. To be sure before spending more money on a sensor, you could swap the pre-cat sensors between banks 1 & 2. The DTC should move with the bad sensor (P1131 or P1132) after two driving cycles. Unfortunately, the downstream and upstream O2 sensors are not electrically interchangeable. There are different part numbers specified.

If the outside end of the sensor is dirty, you might try carefully brushing it clean. The vent could be clogged resulting in a bad reading. The sensor compares the exhaust O2 level with outside are O2 level.

P1151 fixed!

Ok, so I had the same issues as everyone who has posted on this P1151 code thing. Vehicle: 2000 Mounty with 5.0. I cleaned the MAF, throttle body and IAC... to no avail. I changed the plugs (Mine were Bosch and only had 25000 mi on them... they were trashed, electrodes completely gone). I replaced the plugs with Autolite Platinums and it ran better then threw the P1151 AGAIN. Went to Autozone and bought the Bosch OEM sensor for $58.00 and installed it. (By the way, it was pretty easy to remove with just a box wrench) Took it out for a drive and... VOILA! Perfect idle, all the power was restored and NO CODE.

Save some time and REPLACE the sensor. I have a commute of 1.5hr to work every day, this will make the drive MUCH nicer!

O2 Seneors

O'riellys will lend you an O2 Wrench (socket).You put a deposit & get a credit when it's returned.

Pirate

Double check, too, and make sure you don't have any melting wires near the replaced o2 sensor. I did all of mine and one of the wires wandered too close to the exhaust, and melted. If you can, just replace all of them to be on the safer side. I Replaced the wire/cover, and it's running without any problems again.

Also
look for a "ring" of worn off dirt on the front drive shaft. If you see it this would be the bank 2 02 sensor wiring rubbing on the drive shaft. I have seen this quite a few times. The chaffed wire will result in a p1151.

2000StreetRod said:

P1152 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank No. 2

As muskegolake pointed in a previous post, P1151 applies to the upstream (pre-catalytic converter) sensor not the downstream (post-cat) sensor. You replaced the downstream sensor. You are still getting codes associated with the upstream sensor (went from lean to rich). After you clear the memory, it takes two driving cycles before the CEL illuminates but the code gets set on the first drive cycle. To be sure before spending more money on a sensor, you could swap the pre-cat sensors between banks 1 & 2. The DTC should move with the bad sensor (P1131 or P1132) after two driving cycles. Unfortunately, the downstream and upstream O2 sensors are not electrically interchangeable. There are different part numbers specified.

If the outside end of the sensor is dirty, you might try carefully brushing it clean. The vent could be clogged resulting in a bad reading. The sensor compares the exhaust O2 level with outside are O2 level.

Click to expand...

Are you sure the O2 sensors are not interchangeable ? Per RockAuto
BOSCH Part # 15716 - Exact Fit; 10.5"
Two required; 4 Wire; Heated; OE Type - Exact Fit - Downstream Sensor
Left side; 4 Wire; Heated; OE Type - Exact Fit - Upstream Sensor

BOSCH Part # 15717 15.4"
Right side; 4 Wire; Heated; OE Type - Exact Fit - Upstream Sensor
Left side; 4 Wire; Heated; OE Type - Upstream Sensor
Two required; 4 Wire; Heated; OE Type - Downstream Sensor

It appears the only difference, at least for a '97 5.0L is the length of the wire. http://www.rockauto.com/catalog/raframecatalog.php

OutofDate1980 said:

Are you sure the O2 sensors are not interchangeable ? Per RockAuto
BOSCH Part # 15716 - Exact Fit; 10.5"
Two required; 4 Wire; Heated; OE Type - Exact Fit - Downstream Sensor
Left side; 4 Wire; Heated; OE Type - Exact Fit - Upstream Sensor

BOSCH Part # 15717 15.4"
Right side; 4 Wire; Heated; OE Type - Exact Fit - Upstream Sensor
Left side; 4 Wire; Heated; OE Type - Upstream Sensor
Two required; 4 Wire; Heated; OE Type - Downstream Sensor

It appears the only difference, at least for a '97 5.0L is the length of the wire. http://www.rockauto.com/catalog/raframecatalog.php

Click to expand...

I suspect rockauto has their terminology mixed up. Generally, the two upstream sensor are the same and can be switched w each other, and the two downstream sensors can be swapped with each other, but the upstreams cannot be swapped with the downstreams.

bobflood said:

I suspect rockauto has their terminology mixed up. Generally, the two upstream sensor are the same and can be switched w each other, and the two downstream sensors can be swapped with each other, but the upstreams cannot be swapped with the downstreams.

Click to expand...

I guess Autozone is also confused, 15716 is listed for use before cat and also listed for after cat. http://www.autozone.com/autozone/pa...ilterByKeyWord=oxyen+sensor&fromString=search

Note: I used 15716 for B1-S2 & B2-S1&S2. 15717 was used on B1-S1.

It's my understanding the only difference between the sensors is the length of wire. Doesn't mean I'm right, but truly hope so, as sensors are a to get to.