I have a 1999 TL with 122K miles. Both lights came on. With doing extensive research, here is the FIX. If plugs have not been changed at 105K, replace with good Platinums. Your typical sign for the TCS and check Eng. light is a coil misfire. Process of elimination by swapping coils around. If problem follows the coil, that is the bad part. Some times more than 1 will fail. My suggestion is to buy 6 NEW OEM Coils from Ebay at about $37.00 each, Dealer installed are $150.00 each. I changed them, and car runs like brand new, like it did before the random misfires. This will fix about 80% of the issues I am reading.

 

PS. Your EGR valve is not the problem, unless it is clogged when you pull it, If it is clean, it is not the issue.

 

I would suggest having the codes read to find out what the problem is. THEN start the repairs.

 

This might be just a coincidence but could this thread be a reply to another thread? https://acurazine.com/forums/2g-tl-problems-fixes-117/1999-acura-tl-check-engine-light-tcs-light-comes-same-time-627856/

 

Mustang,,thanks for your post

please note NGK are the correct plugs, and your 99 came with NGK Iridiums
later years went NGK Platinum- then gen3 switched to Irids
Most of us buy ngk iridium or iridium ix, about 8 bucks each

use only ngk or denso,,ngk cost less and last longer
any other brand,, is just how soon till it craps out

there is zero reason to buy all 6 coils unless you dropped each of them on the floor during plug change!
seriously, they are like Grandmas fine china,,treat like fragile glass,, or insides get messed up
aftermarket are fine,,in the 50 bucks each range at local stores

if its working = its fine,,if you get multi cyl misfire codes,,track down which coil it really is and replace

Never hurt to use CRC or similar `electrical contact cleaner` on all plug-in connections

 

the egr system must be cleaned every 75kmiles
on your 99 it got done once free under recall when they installed a smooth bore
in the passage to cylinder
but it didnt stop the problem

later years have 6 ports, and all years have the main passage thru the intake manifold
where the major grunge buildup is

 

I had this problem...cleanned my egr passige and whaaallaa!

 

I get this problem after I let the car sit for hours in freezing weather. TCS and Check Eng come on, then the car rides like it is pulling a trailer. After about ten minutes, if I turn the car off, let it sit for a few minutes, then turn it on again, the problem goes away.