Bummer, as most of those issues with what you describe are vacuum leaks. If you are feel up to it a different SC could solve the issue, just take your time.
2001 Mazda Millenia 2.5L Champagne Silver Mica 190,000 miles
2002 BMW 530iA Sterling/black 95,000 miles
2006 Volvo XC70 Blue 136,000 miles
2001 Mazda Millenia 2.5L Brilliant Black 213,000 miles - SOLD
1993 Mazda 626 2.5L ATX 235,000 miles - SOLD