06 Freestar LTD - Ran fine, had plugs/wires replaced, now P0420 DTC

[jcasaccio]

Hi

Just had my plugs and wires replaced as part of 60k maintenance. Went to Midas. They had a really hard time with this, kept getting misfire issues. Finally had it resolved, but the 2nd drive of the car tripped the Engine Service light. I went to the local auto parts store to have them ck the codes and it's a P0420 - Cat efficiency low on bank 1.

I know the Midas folks said they had a lot of misfire issues once they changed the plugs, and kept trying to fix it -finally was a bad new plug in #3 cylinder. I researched this code and found misfire can cause damage to the cat converter. Any other ideas of what changing plugs and wires would do to cause this code? The Midas experience was kind of annoying - took much longer than planned for them to do this and they had many issues.

Said they had to drop engine cradle to get to plugs - could they have damaged the exhaust system in doing so - leaky exhaust can also give this cde - from what I have read.

Thoughts?

Thanks
JC

[GraybeardAv]

Gather up your receipts and facts, and take your 'star to a reputable independent mechanic experienced with Freestars. Then ask for your money back from Midas, with threat of small claims court.

They should not have dropped the engine and messed with anything else to change the rear plugs. The rear plugs are easily accessed by removing the cowling between the hood and windshield.

What prompted you to use them, a coupon?

[balogne_t]

Never use franchise businesses for mechanical work... You'll definately pay to much. Besides the normal costs of running a business with independant mechanics, franchises will be much more expensive due to franchise name, royalties, etc associated with frachises.

[jcasaccio]

Hi Graybeard -

The plugs are not easily accessed with the cowl removed - I tried it. I am very mechanically inclined and have not taken a car in for work since 1996, I do it on my own. I just could not get enough access to get 2/3 back plugs.

It's fine now, they set the computer back to factory settings about 100 mi ago and it seems ok. The tech stated he was a Ford mechanic and that sometimes cumulative data in the computer paired with recent DTC codes/issues can cause the engine light to go off. It seems to run fine now, but we'll see in a few more miles.

I was prompted to use them from trusted neighbor recommendation and plus I didn't want to pay $350 at the dealer.

Thanks!
Jack

[GraybeardAv]

OK, Jack, sorry, I haven't tried it; just reporting what I have read here and on the Windstar Forum. I will try it sooner or later.

Hope it's cured.