DREADED p1140/p1145 CEL's. How do I figure out what I need to buy?

[longhornsqx4]

So my car hasnt relaly been running right (2001 qx4 3.5L), sometimes will die on startup if you dont give it gas, and has a funny idle, and the gas mileage is BRUTAL!!! I get about 250miles to a tank.

Couldnt really afford to take the car to a shop, so I bought this cheap OBD2 reader off the net. And it pulled 4 codes, all which seem expensive....

I just matched the codes I got to the FSM

p0160 - H02S2 (B2) 02 sensor Im assuming, does it say which it is?

p1140 - INTK S/CIRC B1

p1145 - INTK S/CIRC B2

FSM said these were intakecam sensors, do they need replacing are they affecting anything? Are they the same part that i just buy 2 of?

P0100 - MAF Sen/Circuit 3

The dreaded MAF sensor, does that mean its dead and I need a new one? I did remove my airbox from my qx4, unbolted it right before the MAF, but it still has a mesh screen protecting it, maybe its not bad?

Just need some help on the location of the 02 sensor I guess, and if there is a cheap reliable replacement. ANd if the intake sensors do anything and if they would be worth replacing to me.

Thanks alot guys, I really apprecaite it, and thatnks for slickroger for posting the trickdam obd reader, this thing saved me MONEY!!
Modified by longhornsqx4 at 11:17 PM 2/10/2009

[fueler]

the bank 2 sensor 2 is after the cat - and is only there for emissions - does not affect the engine performance at all. maf sensor might need a cleaning

most importantly: how is your vehicle running?

personally, id just clear the codes and see if they come back. i had the same o2 sensor code and after clearing it, it never came back, passes smog fine.

[longhornsqx4]

Ok so that 02 sensor defientely isnt getting replaced if it does nothing, I pushed "clear" codes on this reader I bought, but they were there when i plugged it right back in, is there a way to do it?

I will definetely grab some MAF cleaner tomorrow and try that, I did read about the maxima MAF for about $120 shipped so thats prety good

I just read a big thread on the 1145 and 1140 codes, very confusing actually, need some insight, I still dont know if they actually affect anything...... or what exactly needs replacing

[longhornsqx4]

This is the code reader I bought

http://cgi.ebay.com/ebaymotors...74044

You can see the READ and CLEAR button, didnt come with any manuals though!!

[fueler]

oh man thats the simplest obd reader you can possibly buy, basically all it does is pull the code when you get to the readers that are over $100 (my favorite is ScanGauge) they show everything about your engine while its running, and also have a freeze frame stored of exactly what happened when the check engine light was triggered (engine RPM, vehicle speed, %throttle, coolant temp, intake temp, MAP, o2 sensors, etc)

[nissandoms47]

the 1140-1145 codes are pretty much "VVT" related theyre very easy sensors to replace, located right on the front of the engine. Never heard of them going out though. All your codes might be a tad expensive, but super easy to fix.

[longhornsqx4]

Ya its deifnetely a simple reader, and thats all I really wanted, gimme the code and clear it, for $25 shipped, couldnt beat it at the time (im broke)

I read the manual and it says that the codes get CLEARED automatically after it displays them 4 times, but why does it have a clear buttom then? I dunno, Ill pm someone

About the CEL's, ya i hear there fairly easy to change (maf and 02 sensor anyways)

But the 1140 and 1145, are they worth changing, like are they affecting anything. There the 2 sensors on the front of the motor, and Im assuming I need both of them, but today Im gonna take all 3 sensors out and clean them, see what does

But Id love some info on whether or no they make a difference

[longhornsqx4]

Went out today and tried to clear the codes, I did, and only the 1140/1145 codes came back right away. So far the MAF and 02 code are gone, but I havent really driven the car anywhere, just idled in my driveway, so we will see if it goes away.

I didnt touch the 02 sensor, just cleared it. And the MAF sensor I just pulled out and blew some dust and residue off of it, didnt have any maf safe fluid so I didnt clean it.... but the code went away...

This is the maf right

[nissandoms47]

you need to replace those 2 sensors, they control your camshaft timing.

[Chuck Tribolet]

Go track down Nisstech's discourse on the cam codes before you do ANYTHING.He has some good shadetree debugging on those.

[longhornsqx4]

Yeah Ive seen some of his threads on them, but I really dont even know where the sensors are (Ive never seen them) so I really cant even begin to understand where to begin figuring out what to do

[longhornsqx4]

I dont have a CEL light in my dash, its pulled or burnt out, so I pulled my codes the other day, and got both the dreaded p1140 and p1145

1140 - INTK - S/CIRC - B11145 - INTK - S/CIRC - B2

I cleared my 02 code but these codes are constant. This is on a 20001 Infinity qx4 with the 3.5l VQ35de. Like do I defientely need to buy two new sensors or is it something else... what symptoms would this code give my car?

As it stands right now my car runs like crap, when you start it you gotta give it some gas or it will die, it has a rough/lumpy idle, not the smoothest all the time, but sometiems it purrs when @ 700+rpm or so. Ive had the odd time where it bogs, has died before, wont let you rev...

Im changing the spark plugs in the morning. I just want this to be reliable, need some help

Thanks

[Infinitiguy19]

P1140 Intake Valve Timing Control Position Sensor, RH Bank 1

P1145 Intake Valve Timing Control Position Sensor, LH Bank 2

I would clean there connectors and see if that was the problem, if not then I would seek a pros help or replace your self.

here is where i found out what your codes were: http://www.nicoclub.com/articles.php?id=60332

[longhornsqx4]

I havent even really found a nice REAL picture on what exact sensors they are on the VQ motor,

[longhornsqx4]

But Im sure thats easy enough dont worry about that there, I just need to know if I need to just buy these 2 sensors, or if theres some other problem or how do I figure that out if I got BOTH sensor codes

[qship96]

Generally when one doesnt understand the complete problem or fix, one seeks the help of a trained professional. Why not pay the 1 hour diagnostic fee at dealer for proper analysis, then order parts and complete the repair yourself if you are looking at taking the economy route?

guessing gets expensive real quick.

[longhornsqx4]

This is the location of the 2 sensors right, just removed my engine cover to fix and repaint it anyways so I snapped a pic.

[longhornsqx4]

Im not looking to guess, nor am I in the financial situation to let a stealership guess, or buy parts that I dont need. Ive given the codes I have, engine running conditions. And i just went out and located the 2 sensors.

This is the location of the 2 sensors right, just removed my engine cover to fix and repaint it anyways so I snapped a pic.

[Infinitiguy19]

Easist thing to do is clean the connector and see if that fixes the problem.

If no go then pull out the service manual and a VOM.

If you have no paper service manual go here to obtain and print out the online version: http://www.nicoclub.com/FSM/QX4/

Look in the service manual and see what readings of the sensor should be.

If you need more help, please provide me the year of your vehicle.

[longhornsqx4]

The car is a 2001 Infinity qx4, I tried cleaning the connectors with the proper fluid, let them dry, cleared the codes, but they came right back

[qship96]

Generally when one doesnt understand the complete problem or fix, one seeks the help of a trained professional. Why not pay the 1 hour diagnostic fee at dealer for proper analysis, then order parts and complete the repair yourself if you are looking at taking the economy route?

guessing gets expensive real quick.

Read the above, or continue guessing.

[SteveTheTech]

Generally when one doesn't understand the complete problem or fix, one seeks the help of a trained professional. Why not pay the 1 hour diagnostic fee at dealer for proper analysis, then order parts and complete the repair yourself if you are looking at taking the economy route?

guessing gets expensive real quick.

It's the sad truth of the matter.

This most likely is sludge build up clogging the oil passages in the front cover. If the electrical circuit has both power and ground and the signal wire is verified as not having a short or is open (although highly unlikely given that is appears on both banks). They do share the same power and ground (both could have been compromised while you were installing things). If you are under the hood again take a picture of the underside of the oil cap and the dipstick BEFORE YOU WIPE IT and once while clean.

[longhornsqx4]

I dont really have a camera that could take that quality of a picture

I really do need some help here, I cleaned the sensor connectors very well, and the codes still cannot be erased.

Thanks

[maxnix]

I really do need some help here, I cleaned the sensor connectors very well, and the codes still cannot be erased.

I assure any mid quality OBD II code reader can reset the ECU.

[Infinitiguy19]

Or just don't do anything and let the ECU erase (Forget) the code by its self.

[SteveTheTech]

I assure any mid quality OBD II code reader can reset the ECU.

That signifies a hard fault.

What's you oil level and condition?

[maxnix]

Or just don't do anything and let the ECU erase (Forget) the code by its self.

Just don't think that is going to happen without a reset.

[longhornsqx4]

edited
Modified by longhornsqx4 at 9:52 AM 2/18/2009

[longhornsqx4]

Well my code reader erased the IACV and 02 sensor I had, but these just are always there when I connect the scanner (my ses bulb is pulled on the dash)

And for who asked about my oil level, the oil is fresh 10w-30 castrol, and the level is on the high side but in speck

Ive searched and searched and read and read over the last few days on the 1140 and 1145 ses light Im getting. This is in an 01 QX4 with the vq35de engine.

Ive read so many threads about it being the solenoids, other side banks, not even a problem, fixing the wrong thing, that I just need some help.

Ive personally only done 2 things, tried to clear the codes (they dont clear) and remove and cleaned the wiring harness connectors of each. I am cleaning the right pieces right?



What is my best plan of attack here, Im dead broke and in college, but I cant have my car break down on me or hurt its reliability or break something with these sensors malfuntioning.

Thank you

[fueler]

you say the codes dont clear, but i believe youre using a $30 scan tool, am i correct? Try unhooking the battery for 30 mins and see if that clears it!