I am new to the boards. What a great resource of the modern generation.

I have been having some intermittent problems with my 2000 XJR (104K mi). For the last several months I have been getting "Restricted Performance" and CEL illuminating. When they say Restricted Performance, it is true. Stepping on the gas pedal has little effect on forward motion. It seems to happen more often when stopped at a light. As soon as I start to accelerate, the car stumbles then CEL comes on and then the dreaded "Restricted Performance" message. As I crawl away from the light, I find a place to pull over and shut down and restart the engine. This resets the problem and then I can carry on driving.

I was perplexed in the beginning. No codes!! Just P1000 which I cannot figure out or erase. Finally about a month ago, after several incidents, I finally was able to pull codes. P0172 (Bank 1 too rich) and P0175 (Bank 2 too rich) with P1000 still there. Just a few days ago, the codes were accompanied by a P0101 (Mass Airflow Range Performance).

So I do not want to replace the MAF just to find the codes to return. I have cleaned the MAF about 6-8 months ago with the proper CRC fluid. I suspect O2 sensors. BTW, The exhaust tips do appear to have more soot than normal. I am still getting 15 mpg. Go figure?

Any Ideas where to start?

Thanks!
Doug

 

I just had the same issues. Your maf sensor most likely is dirty. Take your breather hose off and remove the MAF sensor. Get some electronic cleaner that you can spray in there. Do not touch the wires inside the sensor, just spray them a few times, let them dry, spray etc. Clean the air hose out. Make sure your throttle body is clean and make sure the part load breather tube on each side of the cam is clean. Search the forum because there is alot written up about this issue. Once you clean all these parts, and reassemble plug the sensor back in. I would also leave the battery negative cable dissconnected at least 2 hours and let the system reset. It will correct your issue. Mine has run fine the last 3 days after doing all this.

 

Running too rich on both banks? That usually means an air leak upstream from MAF. She is sucking air somewhere. Take the air intake off, clean the MAF (as suggested), and check the intake for any cracks, holes, and such. Also make sure that the MAF gaskets are tight. P1000 is just a self diagnostic code, nothing to worry about.

I'll be in Newport Beach all day tomorrow and I have my scanner with me. If I can be of any help, let me know.

The easiest way to check for the leak, is the "cigar method". With engine off, take off the part load breather hose off, clean the tip (or not if you like the taste of the motor oil!), light up a cigar (a cheap one, NOT Cuban!), and blow smoke into the pipe. The smoke WILL come out wherever the system is breached. The breach could be in many places, but my bet is on the air intake and/or TB.

 

Thanks for the tips coastaljag98 and danielsand. I have cleaned the MAF several months ago. But I can try that again. I will check for leaks as well.

Danielsand - what time will you be leaving Newport today? I get home about 5:45 in Huntington Beach. PM me if you will be available this eve.

Thanks!!

 

This fault can also be caused by the pins on the MAF not making proper strong contact with the connector & this has been cured by slightly bending the pins on the MAF, so they make solid contact with the connector.

Have a read of this article:

Running Rich - P0172 & P0175 | Jeeves and the Jaguar


As stated by Danielsand, P1000 is not an actual fault-it simply means that the system hasn't yet completed all of it's drive cycle tests & that depends on how you drive the car.

 

Well, just to throw this out there in case it is of any help - If you've been driving the car around for months (without a code reset) and it's still showing a P1000, then there may be a sensor that is not reporting it's status to the ECU thus preventing the car from ever completing the drive cycle and changing to a P1111. Even if you have other codes the P1000 should go away after a certain period of time and drive cycles. Just a thought ...

 

I am really impressed with the technical knowledge shared on this forum. It will help us all keeping our felines on the road. Thanks for all the comments. I have work to do. I will let you all know how your suggestions panned out. Thanks! Doug

 

OK gents, I don't like to ask for help but this has me in a quandary!
2000 XKR with 68k miles, Fault codes P0101, P0172, and P0175, rich on both banks and MAF is out of limits, happens after every 3rd drive. Reset faults, runs like a top for 3 drives.....100 miles maybe if you don't stop and shut it off and it will light up the rear end if traction control is off, so I think structurally, the motor is strong.
I have cleaned the throttle body, Cleaned the MAF sensor, Replaced the MAF sensor, replaced the Coolant temp sensor and thermostat, verified the passenger side part load breather tube is clear, (the driver side is smaller and runs under the supercharger and it faults both banks so I didn't think it was worth it), battery is new and strong.

I've reset all codes with carsoft I930.......... 1st trip good, second trip good, ...during 3rd trip get CEL, Reduced Perf Message and all 3 codes again.

I'm starting to get a little miffed at this thing.........And the fact that it happens on every 3rd trip should be a clue, but, hell if I can find out why!!!!

And yes...."Vroom" is my actual last name.

Any advice you can add would be greatly appreciated.

TV

 

Your problem could be due to dirty/corroded pins in the connector that plugs to the MAF. Check the pins and give them a good clean with some electronic cleaning spray. If, perhaps, there is dielectric grease inside the connector, you will have to thoroughly clean it out as this is a wrong place to use the grease. You can also get a new connector at https://www.ebay.co.uk/itm/Toyota-5-...oAAOSw241Yb~zF

It is quite likely that the main problem is what is shown under code P0101 and that the other two codes are just a consequence.

 

Sorry, I forgot to say I cleaned the connector and made sure all receptacle's are tight. I do have a slight puffing noise that sounds like it's under the throttle body. Is that normal?
I've never had a supercharger before.

 

I would guess your injectors are spitting instead of spraying: try a can or two of BG44K or SeaFoam or Gumout's look alike.

Might need to also check fuel pump and replace the fuel filter.

 

Jhartz,
If I didn't have the P0101 fault at exactly the same time I'm with you, but spitting injectors would not cause a P0101 Mass Air Flow out of range fault would it?

 

It is not normal and it suggests that you have some air leak at the TB. There are four gaskets/seals associated with the TB and the intake elbow below it. There are also vacuum lines connected to the elbow including a rigid plastic tube that goes to the brake booster. The gaskets/seals are:

1. Large rectangular gasket between the elbow and the supercharger
2. Gasket between TB and the elbow
3. O-ring between elbow and the bypass valve
4. Large rubber seal on top of the TB for the plastic intake tube

 

I've put it off until after Christmas, but, Thank you for your input. I'm following your lead starting on the 28th,

Tom Vroom

 

Interestingly enough, over on FACEBOOK in the 308 group, a member suggested replacing the purge valve which solved the problem. I seem to remember this issue years ago . . .

 

Yes, a faulty purge valve, or a broken vacuum hose to it, could cause intake vacuum leak. Two of its vacuum hoses are connected to the intake elbow.

 

Perfect, thanks for the info. I'll continue on this right after Christmas. Thank you gentlemen.

 

OK, just thinking, "IF" I have a vacuum leak downstream of the MAFS, and in theory less air is passing over the MAFS, wouldn't the PCM meter "LESS" fuel to the injection system? And, "IF" that is true, why would I get P0172 and P0175 (both banks too rich) at exactly the same time as the P0101 fault.

When you have time you quandary things!

Thanks for any input that might help me.

Tom

 

As the description of code P0101 in the table above states, the ECM will go into a kind of restricted performance or "limp home" mode. Although not mentioned, but I believe that the ECM then ignores the signal from the MAF and goes by its special table for "limp home". I this case, as far as I know. the ECM will deliberately switch to richer mixture to prevent the possibility of engine damage by too lean mixture. It appears that this richer condition then triggers codes P0172 and P0175.

The intake leak is not the only possible cause but, since you have the puffing noise, you should investigate and fix.

If checking/fixing the seals and vacuum hoses around the TB and checking/replacing of the Purge Valve does not solve the problem, you may still have some fault, if not in the MAF itself or in its connector, somewhere along the wiring from the MAF to the ECM.

 

Ah Mr. Stojanovic,

You have truly made the light bulb illuminate and I will follow your lead after Christmas. Now, I'm headed for the garage to finish the timing belt/water pump on brother Honda Accord. He owes me bigtime!

Tom