I replaced the timing belt on my 01 Nissan Xterra. After replacing it the engine starts and idles fine. The problem is I don't have any power when accelerating. The engine bogs down and I have to floor it to get it going. This happens from a dead stop and also on the highway. Sometimes it accelerates fine but most of the time it doesn't. The engine doesn't stall at any point. I've doubled checked everything that I disconnected during the install but I haven't checked the Ignition timing. Could I have put the belt on wrong, maybe a tooth off or something like that. Any suggestions will be appreciated.