turning left - lotsa noise; CEL

Hi,
New here....I've seen other posts about what sounds to be the same problems as I have.. 99 Windstar SEL. 114,600 KM

1) When turn left, whining noise, when turn right, no noise. Seems to be more pronounced when engine / van cold, seems to be not as loud when the van warms up (after driving for about 1/2 hour ++)
--I've seen solutions being tie rods, steering pump, steering rack. I've had some work done on tie rods and bearings, but I can't recall off hand which side and how long ago...I have to look it up

How do you know which it is?? - I don't want to have to pay for parts that aren't it!!!! Any pointers for dealing with the mechanic??

2) My Check Engine Light is on, constantly - Van was starting poorly, not turning over, they changed the alternator and battery, now it starts fine, but the check engine light came back on 2 days later and has been on ever since (a month or so). Any hints? The mechanic hasn't come up with a solution yet.

Thanks so much everyone!!!

I don't have much to say about the steering troubles but for the CEL I suggest that you get your codes read.

I just read your profile and I see you are in Oakville so you can't go to autozone and have them read for free.

Anyway you do need to get your codes read. I ended up buying a code reader to read mine. I got it from Cdn Tire for about $200. I figure it payed for itself over and over.

A 99 has 2 major defects that affect the CEL. There is the Isolator bolt problems and the DPFE. However it would not be a good idea to do anything unless you have those codes.