Exhibit 31.2

I,  David  W.  Whitwell,  certify  that:

1.     I  have  reviewed  this  quarterly  report  on  Form 10-Q of Clean Diesel
Technologies  Inc.:

2.     Based  on my knowledge, this report does not contain any untrue statement
of  a  material  fact  or  omit  to  state a material fact necessary to make the
statements  made, in light of the circumstances under which such statements were
made,  not  misleading  with  respect  to  the  period  covered  by this report;

3.     Based  on  my  knowledge,  the  financial statements, and other financial
information included in this report, fairly present in all material respects the
financial  condition,  results of operations and cash flows of the registrant as
of,  and  for,  the  periods  presented  in  this  report;

4.     The  registrant's  other  certifying officer(s) and I are responsible for
establishing  and  maintaining disclosure controls and procedures (as defined in
Exchange  Act  Rules  13a-15  (e)  and  15d-15  (e))  and  internal control over
financial reporting (as defined in Exchange Act Rules 13a-15 (f) and 15d-15 (f))
for  the  registrant  and  have:
     a)   Designed  such  disclosure  controls  and  procedures  or  caused such
          disclosure  controls  and  procedures  to  be  designed  under  our
          supervision  to  ensure  that  material  information  relating  to the
          registrant,  including its consolidated subsidiaries, is made known to
          us  by others within those entities, particularly during the period in
          which  this  report  is  being  prepared;  and
     b)   designed  such  internal  control  over  financial  reporting,  or
          caused  such  internal control over financial reporting to be designed
          under  our  supervision, to provide reasonable assurance regarding the
          reliability  of  financial  reporting and the preparation of financial
          statements for external purposes in accordance with generally accepted
          accounting  principles;
     c)   evaluated  the  effectiveness  of  the  registrant's  disclosure
          controls  and  procedures and presented in this report our conclusions
          about  the effectiveness of the disclosure controls and procedures, as
          of  the  end  of  the  period  covered  by  this  report based on such
          evaluation;  and
     d)   disclosed  in  this  report  any  change  in the registrant's internal
          control over financial reporting that occurred during the registrant's
          most  recent fiscal quarter (the registrant's fourth fiscal quarter in
          the  case  of  an  annual  report) that has materially affected, or is
          reasonably  likely  to  materially  affect,  the registrant's internal
          control  over  financial  reporting;  and

5.     The  registrant's other certifying officer(s) and I have disclosed, based
on  our  most recent evaluation of internal control over financial reporting, to
the  registrant's  auditors and the audit committee of the registrant's board of
directors  (or  persons  performing  the  equivalent  functions):
     a)   All significant  deficiencies  and  material  weaknesses  in  the
          design  or  operation  of  internal controls over financial reporting,
          which  are  reasonably  likely  to  adversely  affect the registrant's
          ability  to  record,  process,  summarize  and  report  financial
          information;  and
     b)   Any fraud,  whether  or  not  material,  that  involves  management or
          other  employees  who  have  a  significant  role  in the registrant's
          internal  control  over  financial  reporting;

Date:  November 13, 2006                By: /s/ David W. Whitwell
                                            ------------------------------------
                                            David W. Whitwell
                                            Chief Financial Officer,
                                            Senior Vice President and Treasurer