Segment Reporting (Details) - Company`s reportable segments (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Net sales
Net sales	$ 55,284	$ 60,537
Income (loss) from operations
Income (loss) from operations	(4,266)	(7,837)
Depreciation and amortization
Depreciation and amortization	1,286	1,430
Capital expenditures
Capital expenditures	142	236
Total assets	28,369	35,441
Operating Segments [Member] | Heavy Duty Diesel Systems [Member]
Net sales
Net sales	32,614	40,666
Income (loss) from operations
Income (loss) from operations	1,018	(602)
Depreciation and amortization
Depreciation and amortization	1,082	1,238
Capital expenditures
Capital expenditures	48	135
Total assets	42,181	40,182
Operating Segments [Member] | Catalyst [Member]
Net sales
Net sales	25,823	24,322
Income (loss) from operations
Income (loss) from operations	1,026	(1,816)
Depreciation and amortization
Depreciation and amortization	204	192
Capital expenditures
Capital expenditures	94	101
Total assets	41,687	37,637
Operating Segments [Member] | Corporate Segment [Member]
Net sales
Net sales
Income (loss) from operations
Income (loss) from operations	(6,476)	(5,469)
Depreciation and amortization
Depreciation and amortization
Capital expenditures
Capital expenditures
Operating Segments [Member] | Discontinued Operations [Member]
Capital expenditures
Total assets	1,132	1,172
Intersegment Eliminations [Member]
Net sales
Net sales	(3,153)	(4,451)
Income (loss) from operations
Income (loss) from operations	166	50
Capital expenditures
Total assets	$ (56,631)	$ (43,550)