2007 Is 350 Runs Terrible After Changing Spark Plugs

[Boostaddict07]

I didn't disconnect battery but removed coils and replaced 80K mile plugs with new Denso OEM plugs. I sprayed a little throttlr body cleaner around the throttle body and its motorized and doesn't move.

After completing, I drove car and it runs terrible after only replacing plugs. It seems like it is sluggush, didn't downshift when applied gas, seemed to have a miss but no Check engine light came on. The only plugs changed were on the passenger side.

Is there a protocol you have to follow? I'm wondering if I shouldn't put the old plugs back to see if it ran as good as it did before I started replacing plugs.

Did the battery have to be disconnected first B4 starting?

Any help is appreciated folks.

Thanks

[LEX-SV]

It's been over a week, any improvement?

[CrunchySkippy]

Did you check the gap of the plugs before you installed them? Even factory set plugs need to be verified. Simply dropping them could affect the gap.

Stranger things have happened...so you never know. Maybe one was plug had an incorrect gap (too small) and the ECU is compensating the incomplete fuel burn by retarding the timing. I'm just thinking out loud here.

Good luck.

[lenore]

I seriously doubt the plug gap is problem, they come set from the factory to specs (iridium plugs) I am wondering if you have good contact between the plug and coil pack, did you look inside the coils to see if the springs were ok, no corrosion etc. Also when you did the plugs did you remove the intake or do the plugs without removing intake. However if you did drop a plug you could have messed the gap up...or worse...

[smooth1]

I didn't disconnect battery but removed coils and replaced 80K mile plugs with new Denso OEM plugs. I sprayed a little throttlr body cleaner around the throttle body and its motorized and doesn't move.

After completing, I drove car and it runs terrible after only replacing plugs. It seems like it is sluggush, didn't downshift when applied gas, seemed to have a miss but no Check engine light came on. The only plugs changed were on the passenger side.

Is there a protocol you have to follow? I'm wondering if I shouldn't put the old plugs back to see if it ran as good as it did before I started replacing plugs.

Did the battery have to be disconnected first B4 starting?

Any help is appreciated folks.

Thanks

To be honest, your not making it easy to help. In your description you " sprayed a little throttlr body cleaner around the throttle body and its motorized and doesn't move." What ??

Then you go an to say you removed the coils? Did you put them back in right? to and from the correct positions? You sure you didn't cross any? and you plugged them in tight? And use a contact spray or gel? Then you went on to say you only replaced the passenger side plugs? So did you put in 3 plugs? or 6? Why would you only replace one side? And any time your working on the electrical system, you should disconnect the battery. But that has to do with your safety, not your results.

[Boostaddict07]

I only had time to change one bank of plugs. I know I should have replaced all six at one time. I didn't use any gel at end of coil. I didnt notice any springs at the end of the coil come to think of it. I hope they didnt fall out but maybe they are there. The plugs are in tight and did them one at a time to avoid getting them mixed up but wires are not long enough to have the wrong ones plugged in. I consider myself above average in mechanical ability. The thing that concerns me is that I sprayed some CRC Throttle Body Cleaner around throttle plate to clean the blade. Not enough in my opinion to leak down and damage the motor. Also what concerns me is that it almost is not metering the load as when I press on the gas pedal it takes alot for it to actually downshift. Are the shafts sealed around the throttle blade? The other thing is that it almost feels like the direct port injectors aren't kicking in now and car lacks power. Almost like it is just running on one set of injectors. I am hoping I didn't mess the servo motor up on the throttle body. How would I know if I did? Help.... Sorry for the late response on this. I have been driving my Maxima all week due to this. Could one bad plug cause this with the car not downshifting as gas is applied? Also I need to add that the car isn't missing it just lacks power and doesn't want to downshift under load after trying to clean throttle body. This leads me to think I messed up the throttle body. Is there a way to ohm out the connection on it to see if it is gone. That is my concern.

[clubfoot]

Haven't seen any updates, but I would replace the other three plugs first.