Car Jerks! Help! Please!

[imtheking]

98 Gs300

When I accelerate going any speed (go from 60-70, or 30-50 etc) the car begins to jerk a bunch of times. Jerks and shakes I should say. It only does it when stepping on the gas. It feels like its really struggling to get up and its about to cut off. It shifts fine and the RPM goes up and down as usual. The check engine light finally turned on today. There are no noises or anything. One thing I can say is that my dumb a$$ used generic $1.29 spark plugs a few months ago when i did my own tune up. My friend and I are thinking that it could be spark plugs or wires. Can anyone help me with this before I go to the dealer and spend $80 JUST for them to diagnose the problem........Any feedback would be appreciated.

[TurboGS300]

98 Gs300

When I accelerate going any speed (go from 60-70, or 30-50 etc) the car begins to jerk a bunch of times. Jerks and shakes I should say.  It only does it when stepping on the gas.  It feels like its really struggling to get up and its about to cut off.  It shifts fine and the RPM goes up and down as usual. The check engine light  finally turned on today.  There are no noises or anything. One thing I can say is that my dumb a$$ used generic $1.29 spark plugs a few months ago when i did my own tune up. My friend and I are thinking that it could be spark plugs or wires. Can anyone help me with this before I go to the dealer and spend $80 JUST for them to diagnose the problem........Any feedback would be appreciated.

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You probably got a wire on the wrong cylinder,or the wrong gap. Did you wash the motor? How long has it been doing this? Check engine light could be 02 sensors, there are three, that should be replaced around 60 0r 70 thousand miles.

[imtheking]

98 Gs300

When I accelerate going any speed (go from 60-70, or 30-50 etc) the car begins to jerk a bunch of times. Jerks and shakes I should say.  It only does it when stepping on the gas.  It feels like its really struggling to get up and its about to cut off.  It shifts fine and the RPM goes up and down as usual. The check engine light  finally turned on today.  There are no noises or anything. One thing I can say is that my dumb a$$ used generic $1.29 spark plugs a few months ago when i did my own tune up. My friend and I are thinking that it could be spark plugs or wires. Can anyone help me with this before I go to the dealer and spend $80 JUST for them to diagnose the problem........Any feedback would be appreciated.

←

You probably got a wire on the wrong cylinder,or the wrong gap. Did you wash the motor? How long has it been doing this? Check engine light could be 02 sensors, there are three, that should be replaced around 60 0r 70 thousand miles.

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[/qu

The jerking just started yesterday and the check engine light came on today. I never washed the motor. I dont know where to start. Spark plugs will run me $86 from dealer. What do O2 sensors usually go for? Can I replace myself?

[dcfish]

98 Gs300

When I accelerate going any speed (go from 60-70, or 30-50 etc) the car begins to jerk a bunch of times. Jerks and shakes I should say.  It only does it when stepping on the gas.  It feels like its really struggling to get up and its about to cut off.  It shifts fine and the RPM goes up and down as usual. The check engine light  finally turned on today.  There are no noises or anything. One thing I can say is that my dumb a$$ used generic $1.29 spark plugs a few months ago when i did my own tune up. My friend and I are thinking that it could be spark plugs or wires. Can anyone help me with this before I go to the dealer and spend $80 JUST for them to diagnose the problem........Any feedback would be appreciated.

←

You probably got a wire on the wrong cylinder,or the wrong gap. Did you wash the motor? How long has it been doing this? Check engine light could be 02 sensors, there are three, that should be replaced around 60 0r 70 thousand miles.

←

[/qu

The jerking just started yesterday and the check engine light came on today. I never washed the motor. I dont know where to start. Spark plugs will run me $86 from dealer. What do O2 sensors usually go for? Can I replace myself?

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Could be an injector failing

[TurboGS300]

<_< So it has been running fine since you replaced the plugs and all of a sudden yesterday it started doing this? You can troubleshoot the injectors and the spark plugs by unplugging one at a time and listening for a change in the engine rpm or the way it runs. If you notice a change after unplugging and plugging in each plug wire or injector connector then it's working. if you unplug one and there is NO CHANGE then you've found your problem.

[BA_GS400]

for what it's worth, a 'jerking' feeling or 'chug chug chug' kinda thing is generally going to be spark related as opposed to anything fuel related.

You could also try running the engine at night, pop the hood, and look around very closely for any blue spark as a friend revs the engine. Perhaps a wire or spark-plug insulator (ceramic) is allowing the spark to short against something.

[imtheking]

for what it's worth, a 'jerking' feeling or 'chug chug chug' kinda thing is generally going to be spark related as opposed to anything fuel related.

You could also try running the engine at night, pop the hood, and look around very closely for any blue spark as a friend revs the engine.    Perhaps a wire or spark-plug insulator (ceramic) is allowing the spark to short against something.

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you guys are great. Thanks for all your help. I remember a few weeks ago I met a mechanic in the barber shop. To make a long story short, he said that its not a good thing to use generic parts on luxury cars. I remember telling him about how i used cheap spark plugs instead of dealer plugs and he said "does the car drive sluggish or struggle a bit?". Low and behold, look what happened. I think just to be sure, im going to take the car to the dealer and have them tell me what is wrong. At least they will have all the technology to test the chips etc. If its something easy that i can replace, i will do so. But if it requires a mechanic, i will take it to our family mechanic. I would take it to him first, but like i said, the dealer has a few special tools specially made to test lexus parts etc that my mechanic wont have. I will keep you guys updated. For now, my car is in the auto body shop getting repaired from hail damage. :( again, thank you.