I have a strange issue going on with my 2008 Sienna.
A couple years ago, I got code P0354. I looked it up and says in short, coil D malfunction. I pulled the coil out and also pulled the plug. Plug was fouled out. So I replaced that too. Cleared the code. Running good again.
About 8 months ago, the van started just a slight miss, but check engine wasn't on. I put my cheap scanner on it and it didn't show anything. After a couple weeks of driving, the miss got progressively worse and the engine light came on. I checked the codes and got the P0354 again. I pulled the coil and plug. Plug fouled out again. I replace the plug and coil again, but didn't clear the codes. (my brother borrowed my scanner). Van still running rough. After a few min, my brother came back with my scanner. I tested it again, and the same code was there. Maybe the coil or plug I put in was defective? So, I cleared the code and started the van. To my surprise, the van was running good again. All I did was clear the code.
2 months ago, the code is back. I pulled the coil and plug again. Plug looked fine, so I just changed the coil. Remembering what happened the last time, I didn't clear it yet. I started the van and still continued to run rough. I shut it off, cleared the code and started it again. Running perfect. Hmmm..
Just 3 days later, a coil in the back went out. Ok, I am going to replace all the plugs and coils. Major ordeal when you haven't done it before.
a couple days ago, the miss started again. P0354 is back. Pulled the plug out and its fouled out again. I replaced the plug and put the same coil back on an started it. Still missing. I cleared the code again. Van running good again. However, this time, the engine light remains on with no codes to read. I'm sure there is some deep codes in there that my scanner won't read.
Sooo, why does P0354 keep coming back? Why does the van run good again only after clearing the codes? Is there something in the system that could be killing the coil and/or plug?
Thank you all for any assistance.
A couple years ago, I got code P0354. I looked it up and says in short, coil D malfunction. I pulled the coil out and also pulled the plug. Plug was fouled out. So I replaced that too. Cleared the code. Running good again.
About 8 months ago, the van started just a slight miss, but check engine wasn't on. I put my cheap scanner on it and it didn't show anything. After a couple weeks of driving, the miss got progressively worse and the engine light came on. I checked the codes and got the P0354 again. I pulled the coil and plug. Plug fouled out again. I replace the plug and coil again, but didn't clear the codes. (my brother borrowed my scanner). Van still running rough. After a few min, my brother came back with my scanner. I tested it again, and the same code was there. Maybe the coil or plug I put in was defective? So, I cleared the code and started the van. To my surprise, the van was running good again. All I did was clear the code.
2 months ago, the code is back. I pulled the coil and plug again. Plug looked fine, so I just changed the coil. Remembering what happened the last time, I didn't clear it yet. I started the van and still continued to run rough. I shut it off, cleared the code and started it again. Running perfect. Hmmm..
Just 3 days later, a coil in the back went out. Ok, I am going to replace all the plugs and coils. Major ordeal when you haven't done it before.
a couple days ago, the miss started again. P0354 is back. Pulled the plug out and its fouled out again. I replaced the plug and put the same coil back on an started it. Still missing. I cleared the code again. Van running good again. However, this time, the engine light remains on with no codes to read. I'm sure there is some deep codes in there that my scanner won't read.
Sooo, why does P0354 keep coming back? Why does the van run good again only after clearing the codes? Is there something in the system that could be killing the coil and/or plug?
Thank you all for any assistance.
