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Discussion Starter · #1 ·
So cleared one code purge valve.


1) Now dtc p0154 No activity detected I replaced this sensor and code remains.What can I check next for this code..Plug connections are very clean and tight.:help


2)Now that Ive been driving more this codes popped up P1170 I havnt found much on this code.It seems to be 02 sensor related.I only replaced bank 2 senor 1.I know they say to replace all o2's at once but they all look very clean almost new.:help

Beside the three amigos these codes are the only thing standing between this amazing rover form seeing its destiny.Any help or advice would be greatly appreciated.:help

Thanks Jusin,
 

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So cleared one code purge valve.


1) Now dtc p0154 No activity detected I replaced this sensor and code remains.What can I check next for this code..Plug connections are very clean and tight.:help


2)Now that Ive been driving more this codes popped up P1170 I havnt found much on this code.It seems to be 02 sensor related.I only replaced bank 2 senor 1.I know they say to replace all o2's at once but they all look very clean almost new.:help

Beside the three amigos these codes are the only thing standing between this amazing rover form seeing its destiny.Any help or advice would be greatly appreciated.:help

Thanks Jusin,
Unfortunately, if you don't replace both upstream and downstream sensors at once, the codes can remain. Since the 0154 code is bank 2 and the 1170 is bank 1, you should do all four.
 

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'03 Disco SE
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The codes could be caused by an exhaust leak. Usually the manifold-to-head or manifold-to-Y pipe gaskets are the culprits. Sometimes even the welds around the catalytic converters themselves have been known to fail.

Look for black, sooty deposits around mating surfaces. Also you can carefully maneuver your hands around the connections to feel for exhaust escaping. Even a fairly minor leak should be fairly noticeable. Avoid trying to tighten any of the bolts, you're more likely to strip the head or shear a stud than you are to stop the leak. Replacing the gaskets is the best course of action.

If the exhaust side of things checks out, look for vacuum leaks. Make sure there are no cracks in any of the lines and that all of the connections are tight. Make sure that your air box lid is connected tightly and sealed well.

Basically your MAF & O2 sensors are in constant communication to ensure the fuel/air mixture is right. They operate with the assumption that no air is leaking in behind the MAF and no exhaust is leaking out before the O2s. If you have a vacuum or exhaust leak the numbers are thrown off and can lead to all kinds of weird codes.
 

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Discussion Starter · #4 ·
The codes could be caused by an exhaust leak. Usually the manifold-to-head or manifold-to-Y pipe gaskets are the culprits. Sometimes even the welds around the catalytic converters themselves have been known to fail.

Look for black, sooty deposits around mating surfaces. Also you can carefully maneuver your hands around the connections to feel for exhaust escaping. Even a fairly minor leak should be fairly noticeable. Avoid trying to tighten any of the bolts, you're more likely to strip the head or shear a stud than you are to stop the leak. Replacing the gaskets is the best course of action.

If the exhaust side of things checks out, look for vacuum leaks. Make sure there are no cracks in any of the lines and that all of the connections are tight. Make sure that your air box lid is connected tightly and sealed well.

Basically your MAF & O2 sensors are in constant communication to ensure the fuel/air mixture is right. They operate with the assumption that no air is leaking in behind the MAF and no exhaust is leaking out before the O2s. If you have a vacuum or exhaust leak the numbers are thrown off and can lead to all kinds of weird codes.
Thanks for this advise very helpful!

Can I ask you another question? How long should my secondary air check valves be open? pump kicks on when I first start it for about a min.Then I can still here exhaust dumping in the pump at idle and I think during driving.I placed purge valve due to dtc.If unplug one of the vac lines to the check valve it stops the exhaust from entering the pump why it is not running. I can here the purge valve running constantly.
 

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'03 Disco SE
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Keep in mind the "EVAP purge valve" and "SAI solenoid" are two completely different items that serve two very different purposes. I think you're getting them mixed up.

Purge Valve:



Its connected to the purge lines between the intake manifold and EVAP canister. It's job is to switch on/off quickly at startup to allow fuel vapors to enter the manifold under vacuum. Completely independent from the SAI system.

SAI Solenoid:



It's job is to direct vacuum to both SAI valves, allowing them to open so that air from the pump can enter the exhaust stream.

The two SAI valves (metal canisters attached to SAI flex-piping on either head) are one-way check valves, meaning there is NO WAY for exhaust to back up through the system and get to the pump. Even if there's no air coming from the pump creating positive pressure, there is a reed system in both units that keeps the exhaust isolated.

I'm not sure what it is you're hearing, but its definitely not exhaust going to the pump. If that was the case then the extremely hot (700F+) exhaust gasses would melt all of the rubber & plastic components of the SAI system, not to mention the pump itself.

You need to be 100% sure you replaced the correct parts and hooked up the right connectors. If I recall the purge valve & SAI solenoid have an identical connector that is pretty easy to reverse. Also check to make sure you've routed the vacuum lines correctly.
 

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Discussion Starter · #6 ·
Keep in mind the "EVAP purge valve" and "SAI solenoid" are two completely different items that serve two very different purposes. I think you're getting them mixed up.

Purge Valve:



Its connected to the purge lines between the intake manifold and EVAP canister. It's job is to switch on/off quickly at startup to allow fuel vapors to enter the manifold under vacuum. Completely independent from the SAI system.

SAI Solenoid:



It's job is to direct vacuum to both SAI valves, allowing them to open so that air from the pump can enter the exhaust stream.

The two SAI valves (metal canisters attached to SAI flex-piping on either head) are one-way check valves, meaning there is NO WAY for exhaust to back up through the system and get to the pump. Even if there's no air coming from the pump creating positive pressure, there is a reed system in both units that keeps the exhaust isolated.

I'm not sure what it is you're hearing, but its definitely not exhaust going to the pump. If that was the case then the extremely hot (700F+) exhaust gasses would melt all of the rubber & plastic components of the SAI system, not to mention the pump itself.

You need to be 100% sure you replaced the correct parts and hooked up the right connectors. If I recall the purge valve & SAI solenoid have an identical connector that is pretty easy to reverse. Also check to make sure you've routed the vacuum lines correctly.
Thanks agian for reply: I was mistaking with exhaust entering the pump.Its just air..lol.didnt quit understand secondary air.I did replace the the purge valve with the one showing in the first pic and flow is correct.Thing is the purge valve is constantly run or ticking and the valves are staying open through out driving.I can hear flow into the pump sounds like the muffler would.If i pull vac from one of the check valves it stops and if i put my finger over the pulled vac it pushes are back into the pump.What could be causing my purge valve to run constantly making the valves stay open.I dont know if its been doing this sense I put it back together or sense I changed o2 sensor I reset codes and p1170 has not came back.I really want to enjoy my rover.Sense replacing the head gasket it has not ran over a 201* f I put over 150 miles on it.


Note: I need to fill in my info its a 2001 disco 2 134k the orginal owner put over 7000 into it before head bolt broke anywhere from a complete abs to all o2 sensors before it went down.

I really appreciate all the insight this rover will be getting the fam around for years to come just need that smog then I can take my time to work out everything else.


Thank you
 

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'03 Disco SE
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I replaced the valve in the second pic with the one in the first pic.
Not sure what you mean here. You can't use one instead of the other - they're not interchangeable. I was simply saying the connectors were the same so you *may* have accidentally switched up the connectors, so double check that. Leave the valve and solenoid where they are.

Once again the PURGE valve in the first photo has NOTHING to do with the SAI system.

The SOLENOID in the second photo is what controls vacuum flow to the check valves.

What color is the plug you have hooked up to the solenoid? It should be gray.
 

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'03 Disco SE
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573 Posts
Jesus, dude your setup is completely wrong.

You currently have your FUEL PURGE VALVE hooked up to your SAI system. This is WRONG. The purge valve connects between the fuel vapor lines at the back of the engine bay and the intake manifold. The wiring plug is BLACK. Put the thing back and stop touching it - it has nothing to do with the secondary air system.



Where it connects to:



The SECONDARY AIR SOLENOID has 2 nipples and is connected via hard vacuum line to the left & right SAI valve. It has a GRAY connector. I don't see this solenoid in your photo, but find it and put it back correctly.



After you hook everything up correctly your SAI problems will go away.
 

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Discussion Starter · #12 ·
Wow I guess we are only human..lol..I'm a really good mechanic too.lol.too plugs so close with the same connector. THANK YOU so much! Not only did it clear my sai issue but my o2 sensor dtc has not returned plus power peak and idle sounds and runs much better.


NOW the dawn three amigos.Is it possible that amigos are from sitting for 4 years in snowy seasons lil rust on rotors. abs pump is new before she went down.I removed the shuttle valves wires look fine no fluid present.I did do ohm test 3.00 with no pressure and with one or the other compressed 2.00 and with both 1.00.does this sound right.Does it matter on wheel sensors or is there any recommendations for ones to use.If I am going to peel off the rotors think changing them would be better than cleaning them.

Thanks all very thankful!!
 

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'03 Disco SE
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I apologize for being a dick - I didn't want you to do any permanent damage to the engine. Glad you got the system sorted out.

As for the "3 amigos" your resistances sound right, but there could be any number of other faults left in the system. Wheel sensors, worn hubs, loud brakes, low fluid, voltage issues, etc. It might also just be a residual code left over that was never cleared. The systems don't auto-clear so it's possible.

You need to get an ABS scanner to figure out what's going on. Most OBD-2 scanners will not read ABS codes and won't help you, you need a special unit. Advance/Autozone and other retail stores don't have the ability to read ABS codes for free - probably due to liability. You need to get your own system as a specialist will charge you a $100 diagnostic fee for one reading.

The one I have is the Autel AL619, available on Amazon for $144. You can update the software and use it to scan engine codes, ABS codes, SRS codes, etc. It also does live data. Very useful tool to have when dealing with LRs. It helped both read and clear my ABS codes.

Amazon.com: Autel AL619 OBDII/CAN Scan Tool: Automotive

Harbor Freight does have a similar unit (looks to be made by the same company) for $109. If you get the 25% coupon you can get it for well under $100 which would make it a good deal. I have no experiences with it but it may be worth checking out.

OBD II & CAN Scan Tool with ABS
 

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'03 Disco SE
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You're missing the point again.

Even if you replace your entire brake system with brand new parts, the codes will not clear automatically. You will still need a scanner to clear the codes. Buy one, borrow one, pay a mechanic, whatever - you can't fix your problem without one.

As long as the Three Amigos are still on your dash, your ABS/DAC/Traction Control systems WILL NOT WORK.
 

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Discussion Starter · #18 ·
10-4 thanks bos!Ok so I put old 02 back drove about 20 miles and p1170 came back so I check b2 sensor 2 connector clean.Cleared codes filled the tank half way.Drove to work 40 mile turn around no light no codes.yeah!! So went see smog guy said since there's no cel and 1590 abs it would pass but my sensors weren't ready after clear said drive more.So I decided to change plugs sense haven't yet Idk y had champions in it..lol..dealer mechanic . replaced with bosch ir.filled the tank and add a guaranteed to pass smog additive lowers emissions for a tank.drove 60 more miles and hard on the gas and walla no light and all sensors and cat ready.Smog tomorrow!! Really appreciate your time bos.

As for abs I think from sitting for so long sensors are probly gone from snow corrosion. Idk yet but front L sensor has but con. on it been replaced with a cheaper. Proly..going to replace all sensors so I know there new and have a shop a friend clear my codes.


Thanks again will update after smog and three amigos.
 

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Discussion Starter · #19 ·
O ya forgot to mention all my old spark plugs had a rust look to them that wipe right off.I did clean the driver side plugs before head gasket installation. Sign of water haven't lost any coolant or from purge valve only running for one min and 100 miles on 5 cold starts. ouch live n learn
 

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Discussion Starter · #20 ·
Past my smog check yeah!!Smog guy let the abs code slide cause it wasnt cel related.Only thing i did was put my old o2 back in cleared codes drove 100 miles and light back..But a week after my smog cel on again with 01170 bank q sensor 2 back agian rover seems to run alittle rough when code is present.


The sensor itself looks new and connection clean as mentioned before was replaced before break down 5 years ago.I odered a front sensor cause my code p0154 was present before clear now after 200 miles the p1170 only fault right now.

Should I just replace this sensor and use the front one I and change them both.Every bit of gas saved counts being california.
 
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