The Frequency (high vs. low) x Regularity (regular vs. exception) interaction found on naming response times is often taken as evidence for parallel processing of sub-lexical and lexical systems. Using a Go/No-go naming task, we investigated the effect of nonword versus pseudohomophone foils on sub-lexical processing and the subsequent Frequency x Regularity interaction. We ran two experiments: (1) a Go/No-go naming task with nonword foils (e.g., "bint") and (2) a Go/No-go naming task with pseudohomophone foils (e.g., "pynt"). Experiment 1 replicated the Frequency x Regularity interaction on naming response times supporting the notion of parallel sub-lexical and lexical processing. Experiment 2 eliminated the Frequency x Regularity interaction providing evidence for the modulation of sub-lexical information. These results indicate that using pseudohomophones in the Go/No-go naming task minimized information provided from sub-lexical processing and maximized information provided from the lexical system.