Do stealth fighters need active radar jammers?

Some say no.  The idea of stealth is to become invisible on radar.  If the stealth aircraft starts radiating, it can be a give away, similar to violating radio silence at sea.  Jamming can give your position away.  On the other hand,  stealth or no stealth, there comes a point when enemy radar sees you, and is guiding missiles your way.  In this case a range gate stealer, an angle track deflector, a sidelobe jammer, or what ever else has been dreamed up since Viet Nam, can save your bacon.  If you have the equipment on board that is.  If you don't, best to check your ejection seat. 
   The Aviation Week article goes on to criticize the F16 for lacking internal jammers,  and the F15 for having old internal jammers.   Back when I was on the flight line, you put your jammers in pods under the wing.  That way you could upgrade your jammer to meet new threats by just loading a new pod, rather than rewiring the entire aircraft to install new internal jammers. The jammers are most effective against missiles.  A good radar man can often sort the target out from the jamming.  Missiles are dumber than radar men.
  What set off this Aviation Week commentary?  The Malaysian Air Force showed up with new model Russian jamming pods on their Russian built fighters.  The accompanying photo shows a Sukhoi 30 fighter so old that the twin rudders are mounted straight up and down.  The simplest stealth design would have canted the rudders off the vertical, so radar reflections would go down toward the ground, rather than straight back to the enemy radar set.  This bit of stealth has been well known, even to Russians, for at least 10 years, maybe longer. 

Hacking thru the radar

Last week's Israeli Air Force strike in Syria may have used advanced electronic deception transmissions to confuse the up-to-date Russian made Syrian anti aircraft defenses. Systems are known that can invade air defense communications systems, cause them to transmit their radar views back to the attackers, and even issue false orders to cause sensors to look away from attackers, designate radar tracks as friendly, or insert false tracks.
Seeing the enemy radar's view is extremely valuable to attackers, it shows the blind spots in enemy radar coverage and lets the strike aircraft know when they are flying low enough to avoid detection. Radars contain various circuits or software to filter out clutter. It may be possible to crank those filter setting up so high that the attacker's radar tracks are filtered out. Or have the radar label the attackers tracks as friendly airliners. Or simply fill the system with so many false targets that the real attackers are lost in the crowd.
Hard information is a little scarce, Aviation Week is reduced to quoting Arab newspaper articles. "Russian experts are studying why the two state-of-the-art Russian-built radar systems in Syria did not detect the Israeli jets entering Syrian territory" according to the Kuwaiti newspaper Al Watan. It goes on to say "Iran reportedly has asked the same question, since it is buying the same system and might have paid for the Syrian acquisitions".
Syria has recently acquired the Tor-M1 (SA-15 Gauntlet) a mobile system with guidance radar, missile launchers and missile reloads all mounted on tracked vehicles. Tor-1 costs $29 million per system.
The actual site of the attack, and it's contents are still a matter of dispute. Some reports place the attack at Tall Al-Abyad up in the Turkish border, others place it at Day az-Zawr out near the Iraqi border. The site may have contained nuclear material on route from North Korea to Iran, or it may have been a more run-of-the-mill storage for conventional munitions bound for Iraq, or Hezballah, or Iran. News reports are conflicting.
Naturally successful use of secret electronic countermeasures tells the enemy that his system is vulnerable and that codes must be changed and fixes invented. The Syrian target must have been pretty high value for the Israelis to disclose the effectiveness of their electronic countermeasures.