2001 Misfiring P0300, P0171, P0174
03-15-14, 07:55 AM
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2001 Misfiring P0300, P0171, P0174
Well here's a tricky one... I recently fixed the knock sensor errors by replacing the KS harness and sensors, so that's done, but now I'm dealing with misfiring (which was an issue before the KS sensors)... I'm getting errors P0300, P0301, P0303, P0304, and P0171 (Bank 1 fuel trim too lean) and P0174 (A/F lean malfunction, Bank 2, System too lean)...
The car's CEL is blinking, TRAC OFF light illuminated, and it shakes at idle. I'm not driving it around because I know it could damage the exhaust systems... Any pointers?
The car's CEL is blinking, TRAC OFF light illuminated, and it shakes at idle. I'm not driving it around because I know it could damage the exhaust systems... Any pointers?
03-15-14, 09:28 AM
#2
Usually, a P0171 points to either a dirty/malfunctioning MAF or bad O2/AF sensors (these are expected to last about 100K miles).
I'd do the following. After each step check to see if the problem was corrected.
1. Check for vacuum leaks and repair as required.
2. Clean the MAF
3. Replace the bank 1 upstream O2/AF sensor.
4. Replace the bank 2 upstream O2/AF sensor.
5. Replace the MAF.
I'd do the following. After each step check to see if the problem was corrected.
1. Check for vacuum leaks and repair as required.
2. Clean the MAF
3. Replace the bank 1 upstream O2/AF sensor.
4. Replace the bank 2 upstream O2/AF sensor.
5. Replace the MAF.
03-15-14, 04:30 PM
#3
^ Do that first. Run some MAF cleaner. Regarding the O2's, unless the car is 'hot' there's no point in changing them... for an O2 to be tested the car needs to be "hot"... aka 'closed loop' mode since then the O2's are actually reading the fuel ratios. When idling the O2's are in open loop - no reading since it's in park and idling/warming up to get to operating temps...
I've been dealing with the similar deal on mine, just bank 2 misfire.
Not driving is a good call... my cat gets red hot if its at operating temp, and driven for more than 10mins. Luckily I get to drive 4mins to work so she doesn't warm up until then... which is why I get away with it - sort of.
I tried the three coils - didn't fix it. Just delayed the issue for two drive cycles. So now I have three new coils I can't return on the passenger floor in my ES lol.
I ordered the OCV's, since I feel they're the culprit. When testing them they click on/off fine, but I suspect they're on their way out, and simply working intermittently causing a misfire... I'll keep you posted with my findings.
I've been dealing with the similar deal on mine, just bank 2 misfire.
Not driving is a good call... my cat gets red hot if its at operating temp, and driven for more than 10mins. Luckily I get to drive 4mins to work so she doesn't warm up until then... which is why I get away with it - sort of.
I tried the three coils - didn't fix it. Just delayed the issue for two drive cycles. So now I have three new coils I can't return on the passenger floor in my ES lol.
I ordered the OCV's, since I feel they're the culprit. When testing them they click on/off fine, but I suspect they're on their way out, and simply working intermittently causing a misfire... I'll keep you posted with my findings.
03-15-14, 07:40 PM
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^ Do that first. Run some MAF cleaner. Regarding the O2's, unless the car is 'hot' there's no point in changing them... for an O2 to be tested the car needs to be "hot"... aka 'closed loop' mode since then the O2's are actually reading the fuel ratios. When idling the O2's are in open loop - no reading since it's in park and idling/warming up to get to operating temps...
I've been dealing with the similar deal on mine, just bank 2 misfire.
Not driving is a good call... my cat gets red hot if its at operating temp, and driven for more than 10mins. Luckily I get to drive 4mins to work so she doesn't warm up until then... which is why I get away with it - sort of.
I tried the three coils - didn't fix it. Just delayed the issue for two drive cycles. So now I have three new coils I can't return on the passenger floor in my ES lol.
I ordered the OCV's, since I feel they're the culprit. When testing them they click on/off fine, but I suspect they're on their way out, and simply working intermittently causing a misfire... I'll keep you posted with my findings.
I've been dealing with the similar deal on mine, just bank 2 misfire.
Not driving is a good call... my cat gets red hot if its at operating temp, and driven for more than 10mins. Luckily I get to drive 4mins to work so she doesn't warm up until then... which is why I get away with it - sort of.
I tried the three coils - didn't fix it. Just delayed the issue for two drive cycles. So now I have three new coils I can't return on the passenger floor in my ES lol.
I ordered the OCV's, since I feel they're the culprit. When testing them they click on/off fine, but I suspect they're on their way out, and simply working intermittently causing a misfire... I'll keep you posted with my findings.
I checked for vacuum leaks today but no luck. I have cleaned the MAF sensor with MAF sensor cleaner spray, it was pretty gunked up. No change there... I put in new spark plugs and that didn't change anything either. I think my next step is to check the fuel injectors and filter?
03-16-14, 12:31 PM
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What an interesting video! I haven't ruled out the fuel injection system with my issues. Once tomorrow comes around I'm going to do some more troubleshooting. It's way too windy and cold today to get out. I'll keep everyone posted and thanks for the replies! Everyone is so helpful.
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03-16-14, 01:19 PM
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So I went outside in the cold and noticed cylinder 6 injector had a bit of gas around it and for once, it actually had a pretty rough time starting and maintaining idle. There are definitely some major issues going on here.
03-20-14, 08:04 PM
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Awesome.
Do you get code P0420 now? That's the only code coming up now for me and I figure it's because of the excessive emissions from the misfires. I don't really want to dish out money for a new cat...
Do you get code P0420 now? That's the only code coming up now for me and I figure it's because of the excessive emissions from the misfires. I don't really want to dish out money for a new cat...
03-20-14, 08:36 PM
#12
I would suggest a used cat... forget the 400$ aftermarket options. It's not a 20k $ car... This is better & complete;
http://www.ebay.com/itm/2000-2001-LEXUS-ES-ES300-FRONT-EXHAUST-MANIFOLD-CONVERTER-USED-OEM-00-01-/281290292003?pt=Motors_Car_Truck_Parts_Accessories&hash=item417e353b23&vxp=mtr
Or look on car-part, these are sub-1000$ cars at the auction houses... parts are out there, just gotta look. Even your local pick-n-pull.
04-01-14, 07:38 AM
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Thankfully no. I didn't drive the car much and only four times did the cat get 'red hot' in my case. Otherwise it was cold, and I started driving. Seemed to be calm that way... otherwise warmed up it went bonkers.
I would suggest a used cat... forget the 400$ aftermarket options. It's not a 20k $ car... This is better & complete;
2000 2001 Lexus ES ES300 Front Exhaust Manifold Converter Used 00 01 | eBay
Or look on car-part, these are sub-1000$ cars at the auction houses... parts are out there, just gotta look. Even your local pick-n-pull.
I would suggest a used cat... forget the 400$ aftermarket options. It's not a 20k $ car... This is better & complete;
2000 2001 Lexus ES ES300 Front Exhaust Manifold Converter Used 00 01 | eBay
Or look on car-part, these are sub-1000$ cars at the auction houses... parts are out there, just gotta look. Even your local pick-n-pull.
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