Currently you don't see the raw request but in the btc-e exchange file I execute:

    if(type === 'buy') {

      this.btce.trade(pair, 'buy', price, amount, this.errorHandler(this.placeOrder, args, retry, 'placeOrder', handler, finished));

    } else if (type === 'sell') {

      this.btce.trade(pair, 'sell', price, amount, this.errorHandler(this.placeOrder, args, retry, 'placeOrder', handler, finished));

    } else {

      cb(new Error('Invalid order type!'), null);

    }

and I use a third party btc-e api wrapper you can find here:

https://github.com/pskupinski/node-btc-e

In that module you can see the required parameters for the Trade method:

BTCE.prototype.trade = function(pair, type, rate, amount, callback) {
  this.makeRequest('Trade', {
    'pair': pair,
    'type': type,
    'rate': rate,
    'amount': amount
  }, callback);
};

I provide them correctly, so not sure what's wrong.