NEED HELP PLEASE READ 96 4.0 Not Running good at All

[mccoyxx]

Hey ppl. I have a 96 Explorer Sport with a 4.0 ... its a 4wd if that matters ... anyways ... I have been having issues since i got it with it running good .... it seems like its running on like 4 cylinders or something ... I really dunno ... I put the scanner on it and it showed P1151 ... I changed the oxygen sensor behind the cat and it dropped the code and almostinstantly threw a P1152 ... anyways I read on here and posted and ppl. said to clean the MAF ... so I disected it to clean it and its not dirty at all ... looks like new ... anyways its still running so sluggish ... most of the time it doesn't even rev without a 1-2 sec delay. I unplugged the MAF sensor and it seeme like its running noticeably better than it was before unplugging it, but its still having some major issues ... any advice at all ... anyone ... PLEASE ??? ... thanks in advance for your time and have a Happy Thanksgiving ... RSM

 

[2000StreetRod]

upstream of cat not down

P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2
P1152 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank No. 2

You said that you changed the O2 sensor "behind the cat". If you meant aft of the cat then that is not the one that is being identified. The Bank 2 upstream O2 sensor is the one on the driver side that is closest to the exhaust manifold. On my 2000 SOHC it is on the downpipe and very easy to access from under the vehicle.

However, many times the diagnostic code identifies an O2 sensor when the problem is something else. The O2 sensor compares the oxygen content of the exhaust with ambient air. There is an ambient air vent on the sensor. Make sure that your sensor is not covered with caked on mud, road tar or some other residue.

 

[jremington59]

Good call streetrod. It's the easiest one to change by far.

 

[mccoyxx]

ok I also failed to mention that it starts like 5x easier now too ... before i unplugged the MAF it would crank between probably 8-10 times sometimes more before it would run ... now its 2-3 cranks and I also didn't mention that its throwing an EGR code as well and multiple cylinder misfire or random cylinder misfire .. don't remember which .. anyways .. thanks for the input ... will try to get a new O2 sensor soon ... could it really make it run that bad ??? .... I mean it has no power at all unless I kick it to the floor , then it isn't what i would expect by far ... RSM

 

[robertoa1a]

Double check that ath plug wires are going to the right places.

 

[Diemondrio63]

I'd check two things... one, the vacuum at the intake, second, I'd check the EVP... egr vacuum pressure regulator. That damn thing will drive the engine nuts and not always throw a code!

And Happy Thanksgiving to you in return!

 

[marragtop]

How long since the plugs and wires were replaced? Maybe the plugs are fouled due to other issues. Also, check the PCV valve and air filter.

 

[robertoa1a]

Search other threads on the crankshaft position sensor. See if they sound familiar and reply.