Also, to add a little more, when you start it, it runs fine, but only when you accelerate does it sound like it is fuel or air starved and then it backfires.

Pressing the accelerator to the floor produces a dragging affect on the engine and backfiring.

Sensors?

 

Also, to add a little more, when you start it, it runs fine, but only when you accelerate does it sound like it is fuel or air starved and then it backfires.

Pressing the accelerator to the floor produces a dragging affect on the engine and backfiring.

Sensors?

Backfiring...

Cross-firing of the spark plugs, spark going to a plug with an open intake valve..

Burned intake valve(s), ignition of "that" cylinder also igniting the intake mixture.

 

fuel filter or water in gas a possibility. Plug wires?

 

Thanks for the response.

This is the one with Coils on the plug, so my assumption is there are no "plug wires," correct?

Water in the fuel, interesting, didn't think of that one. Fuel filter is also where I am heading. I am also heading to Autozone to see if the alternator is ok.

I will report back on the conclusion.

Thanks.

 

Resolution

Well, it seems the resolution was replacing the O2 sensor Bank 2 Sensor 1 (yea, the one on the rear manifold- pain in the A$$).

$189 for the sensor and it runs again, not well (back to normal I guess), but it runs.

Thanks for the replies.

 

Well, it seems the resolution was replacing the O2 sensor Bank 2 Sensor 1 (yea, the one on the rear manifold- pain in the A$$).

$189 for the sensor and it runs again, not well (back to normal I guess), but it runs.

Thanks for the replies.

this is what seems to be the problem with my shittysienna LOOOL! i had the plugs changed. and it is saying 3 of them are misfiring. it also says i need a new mass air flow sensor which i replaced new. and also the damn sensors too. mine seems to be bank 1 sensor 2 and also bank 1 sensor 1 i think that is at the front of the engine. did you have a hard time getting it off? if so did you spray something on it? thanks

 

Ok I took my car to a mechanic friend of a friend. Very nice man I cannot thank him enough. Well to start off he did a complete tune up again. they top part has to be taken off to get to the back 3 plugs. he said only and i mean only put whatever plugs toyota uses in those cars. nkg i think. so then they got it done and no cel. so i picked it up they replaced the spark plugs a manifold gasket and a temp sending unit or something ( dont remember what it was called 125.00 parts and 190 for labor. i picked her up and not even 8 miles cel came back on. took it back bless his heart he hooked it up and the stupid o2 sensor was showing up. he went to change it ( and now i know why i couldnt change it ) its california emissions. so they got the right sensor plugged it in drove it for the day and the cel still kept comming on. he kept it over night hooked it back up today cel on did a code scan and no code is showing up at all. they are completely baffled at this point. i can tell you one thing that car runs better then when i bought it practically like new. the tune up was AMAZING! and they didnt charge me to keep it or diagnose it nothing just for the o2 sensor not even for putting it on. so he told me today come and pick it up it will take you wherever you want to go. but the light keeps going and comming off and on. and tuesday my buddy who does the electircal work on cars i will pick it up from you on tuesday and take it to him to see if its something electrical. and I wont charge you we trade work with each other. So i brought her home and no check engine light came on.

But I did call toyota they BROKE the rod which holds my hood up. and didnt even tell me its totally gone. I called them yesterday the service guy was off so they took a message he wasnt even going to call me back. I called today and told him I want my rod back to hold up my hood. He said what I said you were the last one to work on it. it was there when i brought it in. now I want it back when i opened it the next day at the mechanics it was not there period. and the mechanic didnt even touch the car yet. so im ticked off a toyota dealership!:headbang:

 

2003 Sennia Symphony hessitaion

My future step father has 130k on the clock of his '03 Symphony. It has hessitation issues that no mechanic in Michigan seems to be able to solve? No Check engine light? Seems to be worse in winter and takes quite awhile to shift into high gear??