What brand of plugs and wires did you install?

 

Year might help.

Looks like it's on one bank? Multiple coils?

 

Here's his other post:
http://www.toyotanation.com/forum/1...forum/103-3rd-4th-generation-1992-1996-1997-2001/1315033-p0171-p0172-p1153.html

 

I have a 99 camry 6 cyl 170K. Recently installed a new EGR and cat converter to pass smog. Last night check engine light came on. Hooked it up to the OBD 2 and I have codes
P0171 System to lean bank 1
P0172 System to rich bank 1
P1153 A/F sensor circuit response malfunction

Do I need a new air fuel sensor? Thank you for any help. Only had the car a couple months so I'm a newb to working on it

Ok thanks. Is that the sensor right behind the radiator at the front of the engine?

I just took it for a drive around the block and its losing power when accelerating from a stop, then it will get full power, then power loss again, and idle is erratic and rough when stopped. Plugs and wires are only a couple weeks old Any advice is much appreciated

would a bad coil cause it to run like this? One of the coils looks a lot older than the other two. Thanks

More info from the code reader
short term fuel trim1 0.0 %
long term fuel trim1 3.1 %

short trim 2 -1.0 %
long trim 2 -40.9 %

short trim 3 -100.6 %
long trim 3 -100.6 %

short trim 4 -100.6 %
long trim 4 -100.6 %

vehicle speed 34 MPH fuel system 1 closed, fuel system 2 closed 1
load value 56.6 %, coolant temp 194 degrees F, intake air temp 96 degrees F

Does anybody know what this means? Is this pinpointing my problem. I dont have a manual for my reader, it was given to me. Looked online but couldnt find a user manual anywhere. Its an Actron cp9175.
I sure hope someone can get me going in the right direction because this is all new to me. Thanks

Would that booster going bad cause a loss of power from the engine?

From his previous thread.

 

Yes those are both my post's. I'm trying to decide if I want to dump a bunch of money into this car or not. Its got 180K miles. I was thinking if I could do it myself it wouldn't cost to much. But this seems to be over my head. Ive been researching for two days how to try and pinpoint the problem but it seems it could be 10 or more things. It was mentioned start with the air/fuel sensor but thats $100 and I dont even know if that is faulty. I could be in it $1K in no time and still have the problem. Is there a troubleshooting flow chart for for camrys or a way to work thru and eliminate suspect parts. It runs good except for the intermittent power loss and rough idle and that makes me want to fix it. Thoughts? Thank you very much everybody for all the advice.
That was a bit long wasnt it.

 

Start with a Compression test for all cylinders. See where you stand as far as the health of the engine itself. If numbers are too way out of wack, there isn't any reason to continue putting anymore money into it.

 

thank you very much. I will do that.

 

Yes, that sounds like a good base. It will rule out half of the worst case (i.e. head gasket, valve problem, etc). Don't think it is any of that, but at lease you'll know it's nothing that requires a major top end overhaul.

 

Those fuel trims are way off. The PCM is pulling nearly all the fuel from that bank, indicating a rich condition.

Does it start okay, hot and cold? That would rule out an injector issue if it does.

Check the 02 voltage on that bank with the engine running. An 02 should switch from .1 to .9 volts, but I'm not sure if an A/F sensor does the same.

 

Mr. G., on the wideband a/f sensor, they normally stay pretty much around 3.3 volts regardless of rpm's, wot, etc., unlike the o2 narrowband sensors which fluctuate rather rhythmically between .1 and .9 with the same types of input.
tony

 

Compression was good in all cyls. So I replaced the A/F sensor, the MAF sensor, replaced all 3 ignition coils, spark plugs and wireset, new battery and cables. Started right up and no codes. Took it for a drive, was running great for about 20-30 mins. Then when I would stop it would idle rough and eventually stall. A P0171 bank1 code came up. It wont start back up until it cools down, but still idles rough. If i let it sit overnight it starts right up and runs good for 20-30 mins then stalls. Doesnt seem to matter if im city or highway driving, its 30 minutes max. I bought the Chilton and Haynes repair manuals for reference.
So thats where Im at right now, any ideas? Fuel injector? I couldnt find a vaccume leak any where but I havent done a smoke test yet. Thanks for the help everybody

 

Compression was good in all cyls. So I replaced the A/F sensor, the MAF sensor, replaced all 3 ignition coils, spark plugs and wireset, new battery and cables. Started right up and no codes. Took it for a drive, was running great for about 20-30 mins. Then when I would stop it would idle rough and eventually stall. A P0171 bank1 code came up. It wont start back up until it cools down, but still idles rough. If i let it sit overnight it starts right up and runs good for 20-30 mins then stalls. Doesnt seem to matter if im city or highway driving, its 30 minutes max. I bought the Chilton and Haynes repair manuals for reference.
So thats where Im at right now, any ideas? Fuel injector? I couldnt find a vaccume leak any where but I havent done a smoke test yet. Thanks for the help everybody

Some reference material and take a look at the bottom of first page!:wink:
http://www.samarins.com/diagnose/p0171.html

=====================================

Another discussing Site for Toyota Camry:

http://www.toyotaownersclub.com/forums/topic/9206-p0171-system-to-lean-bank-1/

 

Test ECT.

 

OK, the previous fuel trims and the lean code don't add up. Code says lean, trims say rich?????

 

OK let me go get the readings again. They may have changed since I added the new parts. Thanks

 

ok here are the latest readings from the scanner I only have the one code now P0171
eng rpm 698
load value 16.0 %
coolant temp 186
intake air temp 82

short term trim 1 0.0%
Long 1 18.7
short 2 2.3
long 2 33.5
short 3 -100.6
long 3 -100.6
short 4 -100.6
long 4 -100.6

vehicle speed 0
fuel system 1 closed
system 2 closed

 

short term trim 1 0.0%
Long 1 18.7
short 2 2.3
long 2 33.5
short 3 -100.6
long 3 -100.6
short 4 -100.6
long 4 -100.6

Long 1 & 2 says lean (vacuum leak?) Long 3 & 4 says way rich. + trim is adding fuel, - trim is subtracting fuel. CA emissions should not add too much to sensor complexity.

Does this engine have a separate cold start injector?

 

Ok today the car wouldnt start. A quick shot of starting fluid and it started right up but after 10 mins of idling in park it started getting rough so I turned it off.
Any advice where I should look/test next? Im thinking I should buy a new ECT sensor since they are not much $. Still only the one P0171 code. If it was the fuel filter or pump wouldnt I be getting a P0174 code too?
Is there a more advanced scan/diagnostic tool I can rent at an auto parts store that would pinpoint the problem? This is becoming absurd. All this CA emissions crap on this car seems to be making it far more difficult to diagnose than it should be

 

You can try this. Find a intake manifold leak. Maybe a 4 cylinder video but the concept is the same.

 

Get a spare ECU off ebay and try that.

Make sure the model number matches.

 

Im not sure if it has a separate cold start injector or not. I will try and find out Thank you

 

There is nothing in the manuals about a cold start injector, so Im guessing there isnt one. There is an igniter. Also about the ECU, where is it? I cant find it, and the manuals dont show its location. Engine compartment, under dash,...or? Is it possible to ruin a MAF with starting fluid?

 

There is nothing in the manuals about a cold start injector

Why don't you switch the O2 sensors right to left/left to right, and see if the fuel trims change banks as well.

Did you test ECT yet?

 

I bought a new ect and will install it tomorrow. If the 02 sensors arent to difficult to get to I will try switching them. Thank you all for the continued help

 

Ok I installed a new ECT and picked up a used ECU and installed it. Car started right up and sounded great. Drove it frwy and city streets for an hour and I was sure that had fixed the problem because of how well it ran. Came home for an hour went to start the car and it wont start and the P0171 is back. Suggestions?
Switching the O2 sensors. Completely remove them and swap them? I didnt know they were interchangeable but I will give it a shot. Thank you

 

My thought is an injector in that bank which is leaking when it warms. It's the most likely way to have a rich mixture in that bank.

 

Thank you, it seems to be about the only thing left is the injectors. There is a tutorial here for injectors on a 4 cyl camry. I have a 6 cyl. Ive never changed injectors on any car. On a scale of 1 to 10 what is the difficulty of changing an injector? If Im changing one, should I change them all?
Thank you all for the help and sticking with me on this mess. If nothing else Ive learned quite a bit

 

The O2s are identical, the back one is a bit hard to get to. It's easier to buy the sensor offered without the connector and splice it in rather than trying to unplug the connector without breaking the socket. . You can buy either. The injectors aren't too hard to get to but you must remove some parts on top of the engine. I'd visit Amazon and buy a used Haynes manual for the car for a few bucks. It will show you how to do this stuff and let you decide ahead of time if you want to try it. I don't like throwing parts at things, but my hunch is the sensor for that bank is failing, and instead of risking breaking something in a swap, I'd just buy a new one before I got into the injectors. The OEM injectors on one of my Camrys have gone 350K, but I've replaced a few O2 sensors.

 

OK I will go buy a couple new sensors first. Before I go replacing the injectors, is having them cleaned professionally an option that might work? Im going to do the screwdriver test on the injectors to see if I can hear them working. Although I have no idea what a working injector should sound like, im hoping they all sound the same lol Thanks for the help

 

O2 Sensors that I know of can't be fixed by cleaning.

Appropriate Codes come up as the Main Engine Management computer would register them via OBD-II and you replace.

My 1992 at the time had a bad ECM and didn't register any codes but, I had horrible gas mileage so, I replaced both (1992 vintage).