horrible idle / engine shake after car audio install

[Split]

So last night I was looking for something to do and i found some old audio equipment, which I decided to install in my wife's yaris.

1) 4channel ampline amp mrv-something -- powering the factory speakers (extremely low gain)
1) 2channel low-end rock fosgate amp bridged powering 1 10" rockford fosgate subwoofer

When I hooked this all up, the car starts to shake terribly when in drive and holding the brake. if i open the hood, the engine is violently shaking back and forth. It doesnt seem to happen in park or neutral, only in Drive when the brakes or ebrake are engaged.

Any suggestions?

[Lil Abner]

Did you take anything apart? Did you remember to tighten the battery bolts down? Did you knock any sensors loose? Unplug any engine sensors? Knock any hoses loose? Does it do it when the stereo is off? Trying first to see if it has anything to do with stereo, and not some other problem that just so happen to come up. :-)

[highwaypass]

i think you should check the electricity system,especially the spark plugs coil. CMIIW

[mazilla]

After you inspect everything for mistakes, try a ground kit, DIY or Ebay for about 20.00...it can't hurt.

[_S7V7N_]

Do you still have the stock battery ?

[defecta]

I am having the same problem after disconnecting the battery before inspecting the factory speaker setup. I have absolutely no mods or changes to the stereo or electricals.

Would I be right in thinking it's just the engine management software having forgotten it's settings? Is it just a matter of time before it corrects itself?

Cheers.

[marcus]

Bet it's the air fuel mixture that the ecu have to get use to.. 20 minutes drive fixes it

[BLH]

After they disconnected my battery during a repair.
My 2007 had to relearn the characteristics of the car and did run poorly at first.

Though I never got any violent engine shakes.

[Split]

^ i took apart the intake and thoroughly cleaned it and the MAF. once i put it back together and reset the ECU everything seems to be fine. I guess it was just a coincidence that it happened right when we installed the stereo.