|
|
Post by Woody Williams on Jul 17, 2021 14:03:19 GMT -5
My 1999 4Runner Check engine light came on and I got the code P0171 System too Lean Bank 1 error code.
I'm not mechanically inclined so I'll take it to a shop but what can I expect?
TY
|
|
|
|
Post by deadeer on Jul 17, 2021 14:29:28 GMT -5
My 1999 4Runner Check engine light came on and I got the code P0171 System too Lean Bank 1 error code. I'm not mechanically inclined so I'll take it to a shop but what can I expect? TY A quick search says possible causes dirty air filter, intake leak, mass airflow sensor, or oxygen sensor, among other things. It's one of those codes that something upstream is telling the 02 sensor something isnt kosher. Definately need to hook it up to a scan tool with a set of knowledgeable eyes to read the sensor outputs. I would guess common, and hopefully a reasonable bill. Good luck. |
|
|
|
Post by bowonlykindofguy1 on Jul 17, 2021 15:34:58 GMT -5
This one is definitely in my wheel house. I would look for a vacuum leak. Pcv hose,throttle air inlet hose an lastly intake manifold gaskets. P0171 indicates the computer can no longer compensate for the extra amount of UNMETERED air into the engine. It also isolates it to only 1/2 of the engine if it is a v-6 the problem will be on the side that has number 1 cylinder. Long fuel trim of over 8 % indicates a vacuum leak. All that being said you can just start it up and spray vacuum lines with brake cleaner and listen for ram change. Isolate your leak then repair it!!
|
|
|
|
Post by Woody Williams on Jul 17, 2021 15:44:51 GMT -5
I’ll give that a try..
But for this newbie what is the PCV line?
|
|
|
|
Post by esshup on Jul 17, 2021 15:48:06 GMT -5
PCV = Positive Crankcase Ventilation line.
Just get the brake cleaner, have the engine running and spray it on the different hoses/gasket areas. When you hear the RPM of the engine increase, that is the leak area.
|
|
|
|
Post by treetop on Jul 17, 2021 16:34:38 GMT -5
My 1999 4Runner Check engine light came on and I got the code P0171 System too Lean Bank 1 error code. I'm not mechanically inclined so I'll take it to a shop but what can I expect? TY You sure are on a run of bad luck |
|
|
|
Post by Woody Williams on Jul 19, 2021 10:53:34 GMT -5
This one is definitely in my wheel house. I would look for a vacuum leak. Pcv hose,throttle air inlet hose an lastly intake manifold gaskets. P0171 indicates the computer can no longer compensate for the extra amount of UNMETERED air into the engine. It also isolates it to only 1/2 of the engine if it is a v-6 the problem will be on the side that has number 1 cylinder. Long fuel trim of over 8 % indicates a vacuum leak. All that being said you can just start it up and spray vacuum lines with brake cleaner and listen for ram change. Isolate your leak then repair it!! Heading to Walmart to get the brake cleaner now. It is a V6 but I'm not sure which side is the number one cylinder? Thanks.. |
|
|
|
Post by bowonlykindofguy1 on Jul 19, 2021 11:18:39 GMT -5
Number 1 cylinder will be the spark plug that is closest to the front of the engine. OR Closest to the belt.
|
|
|
|
Post by deadeer on Jul 19, 2021 12:19:26 GMT -5
Number 1 cylinder will be the spark plug that is closest to the front of the engine. OR Closest to the belt. V6 |
|
|
|
Post by bowonlykindofguy1 on Jul 19, 2021 18:25:33 GMT -5
Number 1 cylinder will be the spark plug that is closest to the front of the engine. OR Closest to the belt. V6 even on a very engine or v8 engine the cylinders are still offset,so even though there are 2 heads they can't be straight across from each other they will be staggered. |
|
|
|
Post by bowonlykindofguy1 on Jul 19, 2021 18:25:51 GMT -5
V6
|
|
|
|
Post by deadeer on Jul 19, 2021 18:44:11 GMT -5
even on a very engine or v8 engine the cylinders are still offset,so even though there are 2 heads they can't be straight across from each other they will be staggered. I know what your saying, but that could be hard to tell for average Joe. |
|
|
|
Post by bowonlykindofguy1 on Jul 20, 2021 21:02:41 GMT -5
even on a very engine or v8 engine the cylinders are still offset,so even though there are 2 heads they can't be straight across from each other they will be staggered. I know what your saying, but that could be hard to tell for average Joe. True,sometimes I forget I been doing it for 30 years! |
|
|
|
Post by Woody Williams on Jul 31, 2021 8:58:01 GMT -5
I haven’t got around to chasing down the cause as I only drive it maybe once a week.
Anywho, I cleared the error a couple weeks ago and I’ve driven the 4Runner maybe a 100 miles since then. The check engine light has not come back on.
Do I have an intermittent problem or was it just a glitch?
|
|
|
|
Post by bowonlykindofguy1 on Jul 31, 2021 10:46:23 GMT -5
More than likely it is an intermittent issue. Have seen instances where the engine will suck air passed a gasket until it warms up some,then when pieces expand with heat it can seal up again. Have also seen where a vacuum hose will only leak after it is fully warm and the rubber softens up a bit. I usually tell people a yellow engine light is usually an emissions concern and if it runs good don't be to concerned. A red engine light is either oil pressure or temperature related,so obviously if red get it looked at.
|
|
